Product item status

ABSTRACT

A method of maintaining a status of a product item, the product item including an associated interface surface, the interface surface having disposed thereon or therein coded data including a plurality of coded data portions, each coded data portion being indicative of an identity of the product item, the method including, in a sensing device:  
     (a) sensing at least one coded data portion;  
     (b) generating, using the sensed coded data portion, indicating data indicative of the product item identity; and,  
     (c) transferring the indicating data to a computer system, the computer system being responsive to the indicating data to update product status information stored in a data store.

FIELD OF INVENTION

[0001] This invention relates to unique object identification and, inparticular, to methods and systems for identifying and interacting withobjects.

CO-PENDING APPLICATIONS

[0002] Various methods, systems and apparatus relating to the presentinvention are disclosed in the following co-pending applications filedby the applicant or assignee of the present invention simultaneouslywith the present application: HYG001US, HYG002US, HYG003US, HYG004US,HYG005US, HYG006US, HYG007US, HYG008US, HYG009US, HYG010US, HYG012US,HYG013US, HYG014US, HYG015US, HYG016US, HYC001US, HYC002US, HYC003US,HYC004US, HYC005US, HYC006US, HYC007US, HYC008US, HYC009US HYC010US,HYC011US, HYT001US, HYT002US, HYT003US, HYT004US HYT005US, HYT006US,HYT007US, HYT008US, IRA001US, IRA002US, IRA003US, HYJ001US, HYJ002US,HYD001US

[0003] The disclosures of these co-pending applications are incorporatedherein by cross-reference. Each application is temporarily identified byits docket number. This will be replaced by the corresponding USSN whenavailable.

CROSS-REFERENCES

[0004] Various methods, systems and apparatus relating to the presentinvention are disclosed in the following co-pending applications filedby the applicant or assignee of the present invention. The disclosuresof all of these co-pending applications are incorporated herein bycross-reference.

[0005] The disclosures of all of these co-pending applications andgranted patents are incorporated herein by cross-reference. 10/409,87610/409,848 10/409,845 09/575,197 09/575,195 09/575,159 09/575,13209/575,123 09/575,148 09/575,130 09/575,165 09/575,153 09/693,41509/575,118 09/609,139 09/608,970 09/575,116 09/575,144 09/575,13909/575,186 09/575,185 09/609,039 09/663,579 09/663,599 09/607,85209/575,191 09/693,219 09/575,145 09/607,656 09/693,280 09/609/13209/693,515 09/663,701 09/575,192 09/663,640 09/609,303 09/610,09509/609,596 09/693,705 09/693,647 09/721,895 09/721,894 09/607,84309/693,690 09/607,605 09/608,178 09/609,553 09/609,233 09/609,14909/608,022 09/575,181 09/722,174 09/721,896 10/291,522 10/291,51710/291,523 10/291,471 10/291,470 10/291,819 10/291,481 10/291,50910/291,825 10/291,519 10/291,575 10/291,557 10/291,661 10/291,55810/291,587 10/291,818 10/291,576 10/291,589 10/291,526 6,644,5456,609,653 6,651,879 10/291,555 10/291,510 19/291,592 10/291,54210/291,820 10/291,516 10/291,363 10/291,487 10/291,520 10/291,52110/291,556 10/291,821 10/291,525 10/291,586 10/291,822 10/291,52410/291,553 10/291,511 10/291,585 10/291,374 10/685,523 10/685,58310/685,455 10/685,584 NPA133US 09/575,193 09/575,156 09/609,23209/607,844 09/607,657 09/693,593 NPB008US 09/928,055 09/927,68409/928,108 09/927,685 09/927,809 09/575,183 09/575,160 09/575,15009/575,169 6,644,642 6,502,614 6,622,999 09/575,149 10/322,450 6,549,935NPN004US 09/575,187 09/575,155 6,591,884 6,439,706 09/575,196 09/575,19809/722,148 09/722,146 09/721,861 6,290,349 6,428,155 09/575,14609/608,920 09/721,892 09/722,171 09/721,858 09/722,142 10/171,98710/202,021 10/291,724 10/291,512 10/291,554 10/659,027 10/659,02609/693,301 09/575,174 09/575,163 09/693,216 09/693,341 09/693,47309/722,087 09/722,141 09/722,175 09/722,147 09/575,168 09/722,17209/693,514 09/721,893 09/722,088 10/291,578 10/291,823 10/291,56010/291,366 10/291,503 10/291,469 10/274,817 09/575,154 09/575,12909/575,124 09/575,188 09/721,862 10/120,441 10/291,577 10/291,71810/291,719 10/291,543 10/291,494 10/292,608 10/291,715 10/291,55910/291,660 10/409,864 10/309,358 10/410,484 10/683,151 10/683,04009/575,189 09/575,162 09/575,172 09/575,170 09/575,171 09/575,16110/291,716 10/291,547 10/291,538 10/291,717 10/291,827 10/291,54810/291,714 10/291,544 10/291,541 10/291,584 10/291,579 10/291,82410/291,713 10/291,545 10/291,546 09/693,388 09/693,704 09/693,51009/693,336 09/693,335 10/181,496 10/274,119 10/309,185 10/309,066NPW014US NPS047US NPS048US NPS049US NPS050US NPS051US NPS052US NPS053USNPS054US NPS045US NPS046US NPT037US NPA138US NPA136US

[0006] Some application has been listed by docket numbers, these will bereplace when application number are known.

BACKGROUND

[0007] The reference to any prior art in this specification is not, andshould not be taken as, an acknowledgement or any form of suggestionthat the prior art forms part of the common general knowledge.

[0008] For the purposes of automatic identification, a product item iscommonly identified by a 12-digit Universal Product Code (UPC), encodedmachine-readably in the form of a printed bar code. The most common UPCnumbering system incorporates a 5-digit manufacturer number and a5-digit item number. Because of its limited precision, a UPC is used toidentify a class of product rather than an individual product item. TheUniform Code Council and EAN International define and administer the UPCand related codes as subsets of the 14-digit Global Trade Item Number(GTIN).

[0009] Within supply chain management, there is considerable interest inexpanding or replacing the UPC scheme to allow individual product itemsto be uniquely identified and thereby tracked. Individual item taggingcan reduce “shrinkage” due to lost, stolen or spoiled goods, improve theefficiency of demand-driven manufacturing and supply, facilitate theprofiling of product usage, and improve the customer experience.

[0010] There are two main contenders for individual item tagging:visible two-dimensional bar codes, and radio frequency identification(RFID) tags.

[0011] There are a significant number of different bar code symbologies,which allow data to be encoded as 2D visible markings, and theseinclude, for example:

[0012] “Code 49” described in U.S. Pat. No. 4,794,239;

[0013] “Data Matrix” described in U.S. Pat. No. 4,939,354, U.S. Pat. No.5,053,609 and U.S. Pat. No. 5,124,536;

[0014] “Datastrip Code”, as described for example in U.S. Pat. No.4,692,603, U.S. Pat. No. 4,728,783, U.S. Pat. No. 4,754,127, and U.S.Pat. No. 4,782,221;

[0015] “huecode” described in U.S. Pat. No. 5,369,261 and U.S. Pat. No.5,118,369;

[0016] “Maxicode” described in U.S. Pat. No. 4,874,936, U.S. Pat. No.4,896,029 and U.S. Pat. No. 4,998,010;

[0017] “MiniCode” described in U.S. Pat. No. 5,153,418, U.S. Pat. No.5,189,292 and U.S. Pat. No. 5,223,701; and,

[0018] “PDF 417” described in U.S. Pat. No. 5,243,655.

[0019] Bar codes have the advantage of being inexpensive, but requireoptical line-of-sight for reading and in some cases appropriateorientation of the bar code relative to the sensor. Additionally theyoften detract from the appearance of the product label or packaging.Finally, damage to even a relatively minor portion of the bar code canprevent successful detection and interpretation of the bar code.

[0020] RFID tags have the advantage of supporting omnidirectionalreading, but are comparatively expensive. Additionally, the presence ofmetal or liquid can seriously interfere with RFID tag performance,undermining the omnidirectional reading advantage. Passive(reader-powered) RFID tags are projected to be priced at 10 cents eachin multi-million quantities by the end of 2003, and at 5 cents each soonthereafter, but this still falls short of the sub-one-cent industrytarget for low-price items such as grocery. The read-only nature of mostoptical tags has been cited as a disadvantage, since status changescannot be written to a tag as an item progresses through the supplychain. However, this disadvantage is mitigated by the fact that aread-only tag can refer to information maintained dynamically on anetwork.

[0021] The Massachusetts Institute of Technology (MIT) Auto-ID Centerhas developed a standard for a 96-bit Electronic Product Code (EPC),coupled with an Internet-based Object Name Service (ONS) and a ProductMarkup Language (PML). Once an EPC is scanned or otherwise obtained, itis used to look up, possibly via the ONS, matching product informationportably encoded in PML. The EPC consists of an 8-bit header, a 28-bitEPC manager, a 24-bit object class, and a 36-bit serial number. For adetailed description of the EPC, refer to Brock, D. L., The ElectronicProduct Code (EPC), MIT Auto-ID Center (January 2001), the contents ofwhich are herein incorporated by cross-reference. The Auto-ID Center hasdefined a mapping of the GTIN onto the EPC to demonstrate compatibilitybetween the EPC and current practices Brock, D. L., Integrating theElectronic Product Code (EPC) and the Global Trade Item Number (GTIN),MIT Auto-ID Center (November 2001), the contents of which are hereinincorporated by cross-reference. The EPC is administered by EPCglobal,an EAN-UCC joint venture.

[0022] EPCs EPCs are technology-neutral and can be encoded and carriedin many forms. The Auto-ID Center strongly advocates the use of low-costpassive RFID tags to carry EPCs, and has defined a 64-bit version of theEPC to allow the cost of RFID tags to be minimized in the short term.For detailed description of low-cost RFID tag characteristics, refer toSarma, S., Towards the 5c Tag, MIT Auto-ID Center (November 2001), thecontents of which are herein incorporated by cross-reference. For adescription of a commercially-available low-cost passive RFID tag, referto 915 MHz RFID Tag, Alien Technology (2002), the contents of which areherein incorporated by cross-reference. For detailed description of the64-bit EPC, refer to Brock, D. L., The Compact Electronic Product Code,MIT Auto-ID Center (November 2001), the contents of which are hereinincorporated by cross-reference.

[0023] EPCs are intended not just for unique item-level tagging andtracking, but also for case-level and pallet-level tagging, and fortagging of other logistic units of shipping and transportation such ascontainers and trucks. The distributed PML database records dynamicrelationships between items and higher-level containers in thepackaging, shipping and transportation hierarchy.

[0024] IBM Business Consulting Services, in conjunction with the Auto-IDCenter, has carried out a number of case studies analysing andquantifying the costs and benefits of RFID-carried EPCs in the supplychain. They distinguish the benefits which accrue at different stages inthe supply chain (e.g. distribution versus retail), at different levelsof tagging (i.e. pallet versus case versus item), in response todifferent sources of loss (e.g. shrinkage versus unsaleables), andacross different product categories (e.g. grocery versus apparel versusconsumer electronics).

[0025] Since the Auto-ID Center exclusively advocates RFID-carried EPCs,the case studies do not clearly distinguish the benefits which accruefrom EPCs alone from the benefits which accrue specifically from RFIDtags. In addition, the case studies implicitly adopt a very optimisticview of the omni-directional scanning performance of RFID in thepresence of radiopaque product, i.e. typically liquid content and metalpackaging. More broadly, the case studies do not clearly recognisebenefits already beginning to accrue from systemic supply chain changes,such as better utilisation of UPC-based scan data collected at thepoint-of-sale, increasingly automated reordering and replenishment, andimproving levels of communication and data sharing between differentparticipants in the supply chain. In many cases these changes arepresented as if predicated on Auto-ID technologies such as RFID-carriedEPCs, when in fact they are not. This in turn tends to overstate thebenefits of these technologies.

[0026] The case studies implicitly assume that tagged units can beaccurately scanned in bulk e.g. when a pallet-load of tagged cases ismoved within a distribution center. However, a study by AlienTechnology, the first manufacturer of RFID tags conforming to theAuto-ID Center's UHF RFID specifications, shows that cases of radiopaqueproduct (such as soft drinks, shampoo, detergent, and coffee in metalcontainers) can only be effectively scanned when the case tags arewithin line-of-sight of tag readers as discussed in Alien Technology,“RFID Supply Chain Applications—Building Test 1”, February 2002. Inpractice this means that pallets of radiopaque product must be split sothat individual cases can be conveyed past tag readers, precludingpallet-level operations including storage and dock-to-dock transfer.

[0027] Although not directly explored in the Alien study, the samerestrictions apply at the item level. For example, while the case studyon obsolescence Alexander, K. et al., Applying Auto-ID to Reduce LossesAssociated with Product Obsolescence, MIT Auto-ID Center, November 2002,assumes that shelf scanners in a retail store can perform a completescan of shelf stock, and the case study on shrinkage Alexander, K. etal., Applying Auto-ID to Reduce Losses Associated with Shrink, MITAuto-ID Center, November 2002, assumes that exit scanners in a retailstore can successfully read items jumbled together in a shopping cart orin grocery bags, in reality the presence of radiopaque product is likelyto undermine performance in these situations, thereby compromising someof the claimed benefits of RFID. The Auto-ID Center's own study ofsupermarket shelf reader design factors concludes that UHF radiopaqueproduct items should have their RFID tags attached to their tops withinline-of-sight of shelf readers Cole, P., A Study of Factors Affectingthe Design of EPC Antennas & Readers for Supermarket Shelves, MITAuto-ID Center, 1 Jun. 2002.

[0028] As with case-level RFID scanning in the distribution center,item-level RFID scanning in the retail store works best when items arehandled individually, such as during stock movement to and from shelves,and during the checkout process, i.e. where each item is allowed to fallwithin line-of-sight of the reader.

[0029] The case studies generally conclude that benefits accruepredominantly from case-level tagging when the case is the primary unitof product movement, which remains true right through the supply chainto the retail store backroom.

[0030] Benefits from item-level tagging begin to accrue in the retailstore once cases are split and product hits the shelves, and thesebenefits fall into three main categories: a reduced shrinkage rate; areduced unsaleable rate; and reduced out-of-stocks (with less safetystock). These benefits are discussed in detail below.

[0031] Stage-relevant tagging levels are illustrated in FIG. 100.

[0032] The case studies assume seven product categories, summarised inTable 1. For every product category except grocery, the case studiesconclude that item-level tagging is cost-effective. Specifically, thecase studies do not consider item-level RFID tagging in grocery to becost-effective because of the high cost of RFID tags relative to theaverage item price.

[0033] Note that if partial and incremental item-level RFID tagging ofhigher-value grocery items occurs (such as of packets of razor bladesAlien Technology, “Alien Announces Major Order for Low-cost RFID Tags”,6 Jan. 2003, http://www.alientechnology.com/library/pr/alien₁₃gillette.htm, then from the point of view of per-tag cost it becomesmore difficult to justify item-level tagging of remaining products,since the average price of untagged items has been reduced. Conversely,it may become easier to justify from the point of view of sunkinvestment in reader infrastructure. TABLE 1 Product categories andaverage item prices average product category item price grocery $1.75apparel $14 consumer electronics $130 health & beauty $9 music & video$18 pharmacy $27 toys $18

[0034] The case studies therefore make a convincing argument forcase-level RFID tagging for all product categories. Additionallyitem-level RFID tagging may be used for more expensive items.

[0035] With item-level tagging, each product item is assigned a uniqueEPC at time of manufacture. The item's EPC then serves as a key into adistributed PML database which records the characteristics of the itemand its evolving history as it proceeds through the supply chain. Thisincludes the item's inclusion in a dynamic hierarchy of packaging,shipping and transportation units, each identified by its own uniqueEPC. Tracking of higher-level units through the supply chain implicitlysupport the tracking of lower-level units. For example, once a pallet isloaded and until it is unloaded and split, pallet-level tracking issufficient to also track its case-level content. Similarly, once acarton is filled and until it is re-opened and split, case-leveltracking is sufficient to also track its item-level content. Readersinstalled in entry and exit portals in factories, warehouses,distribution centers and retail stores can automatically track unitmovements and update movement histories. Notwithstanding issues withautomatically tracking radiopaque product, RFID readers have benefitsfor pallet-level and case-level tracking.

[0036] At the checkout, the unique EPC of the item prevents it frombeing recorded as a sale more than once. This allows the checkout to bepartially or fully automated. Automatic scanning of a traditional UPCbar code, which only identifies item class, is problematic becausemultiple scans of the same item are difficult to avoid and impossible todetect from the bar code alone. In an automatic checkout the EPC of anitem is typically read many times to ensure that the EPC is read at all,but is only recorded as a sale once. The unique EPC also prevents thecheckout operator from multi-scanning a single item to account for anumber of similar items, a common time-saving practice which can lead toinventory inaccuracy and thereby undermine automatic reordering andreplenishment.

[0037] It has been suggested that an RFID-based automatic checkoutprocess can be as simple as wheeling a shopping cart full of RFID-taggedproduct items through a checkout zone continuously scanned by one ormore RFID readers.

[0038] In reality, due to issues with radiopaque grocery items, anRFID-based automatic checkout is likely to require each item to passthrough the RFID reader's field individually. This may happen when thecustomer places the item in the cart, i.e. if the cart incorporates areader, but is more likely to happen at the checkout where the operatoror customer either places each item on a conveyor to transport the itemthrough the reader's field, or manually presents each item to thereader's field.

[0039] Similarly, whilst the use of item-level RFID tagging arguablymakes it possible to construct so-called smart shelves which incorporateRFID readers and continuously monitor RFID-tagged shelf content,practically this is once again subject to performance in the presence ofradiopaque product.

[0040] The cost of the RFID tag approach is particularly of importancein the grocery sector which is characierised by high-volume sales oflow-priced product items, coupled with low net margins. In 2001-2002 theUnited States grocery sector achieved net profits of 1.36% on net salesof roughly $500 billion.

[0041] During the same period the grocery sector experienced a shrinkagerate of 1.42% and an unsaleable rate of 0.95% Lightburn, A., 2002Unsaleables Benchmark Report, Joint Industry Unsaleables SteeringCommittee 2002. Net profit and shrinkage were therefore roughly equal at$7 billion each, and unsaleables accounted for an additional $5 billion.Out-of-stocks were further estimated to result in a 3% loss in net salesGrocery Manufacturers of America (GMA), Full-Shelf Satisfaction—ReducingOut-of-Stocks in the Grocery Channel (Executive Summary), 2002, whichtranslates into a $200 million reduction in net profit. The grocerysector is also highly labour-intensive, with labour costs accounting formore than 50% of operating expenses.

[0042] Profitable operation in the grocery sector therefore relies onmaximising efficiency, minimising losses due to shrinkage, minimisinglosses due to unsaleables, and minimising out-of-stocks while minimisinglevels of safety stock.

[0043] Table 2 summarises these sources of loss in the grocery sector.TABLE 2 Sources of loss in the grocery sector approximate cost source ofloss contribution ($millions) shrinkage 1.42% 7,000 unsaleables 0.95%5,000 out-of-stocks 0.04% 204 total 2.41% 12,204

[0044] The grocery sector is likely to significantly reduce thesesources of loss over the coming decade, independently of item-leveltagging, by better utilising UPC-based scan data collected at thepoint-of-sale, by increasing the level of automation of reordering andreplenishment, and by improving communication between differentparticipants in the supply chain. Furthermore, the benefits ofitem-level tagging itself only accrue if such systemic changes actuallytake place.

[0045] However, the cost of apply RFID tags to provide item leveltagging to further enhance loss reduction is currently cost prohibitive.

[0046] As shown in Table 2, the cost of shrinkage, unsaleables andout-of-stocks amounts to about 2.41% of net sales. Assuming an averagegrocery item price of $1.75, this cost equates to about 4.2 cents.Further assuming universal tagging of grocery items, and ignoring othercosts and benefits of item-level tagging, such as the cost of the readerinfrastructure and the benefit of an improved consumer experience, 4.2cents represents an absolute upper limit on the threshold cost of a tagin the grocery sector.

[0047] The Auto-ID Center hopes to achieve a 5 cent EPC-compatiblepassive RFID tag within the next couple of years, and Alien Technologyare moving towards that goal with a tag design which they expect toprice at 10 cents in multi-billion tag volumes by the end of 2003. AlienTechnology, 915 MHz RFID Tag, .Ghassali, M., Unsaleables “The U.S.Experience”, Unilever Bestfoods North America, 27 Mar. 2001. However,the 5 cent tag goal is still highly speculative, and even inmulti-billion tag volumes there is currently no projected timeline forachieving an RFID tag price lower than 5 cents. Despite this, the IBMAuto-ID case studies assume a two cent RFID tag within a couple of yearsin their most optimistic scenarios Alexander, K. et al., ApplyingAuto-ID to Reduce Losses Associated with Shrink, MIT Auto-ID Center,November 2002.

[0048] Since even wildly optimistic projected cost savings onlymarginally justify the cost of the most optimistically-priced RFID tags,it is unlikely that universal item-level RFID tagging in the grocerysector is justified in the foreseeable future.

[0049] In addition to this however, other disadvantages of the RFIDtagging scheme, such as the difficulty of scanning in the presence ofradiopaque products, and issues surrounding privacy, make the use ofRFID tags undesirable in item-level tagging of more expensive productseven where the RFID cost becomes negligible.

[0050] It is therefore desirable to find an alternative to the use ofRFID tags for item level tagging which ensures reliable itemidentification, which does not suffer from drawbacks such as reducedprivacy for the consumer. It is also preferable that the techniqueprovides a lower cost alternative thereby allowing it to be economicallyused on grocery items.

SUMMARY OF THE INVENTION

[0051] In a first aspect the present invention provides a method ofrequesting assistance relating to a product item, the product itemincluding an associated interface surface, the interface surface havingdisposed thereon or therein coded data indicative of an identity of theproduct item, the method including, in a sensing device:

[0052] (a) sensing at least some of the coded data;

[0053] (b) generating, using the sensed coded data, indicating dataindicative of the product item identity; and,

[0054] (c) transferring the indicating data to a computer system, thecomputer system being responsive to the indicating data to causeprovision of assistance.

[0055] In a further aspect the present invention provides method ofproviding assistance relating to a product item, the product itemincluding an associated interface surface, the interface surface havingdisposed thereon or therein coded data indicative of an identity of theproduct item, wherein the method includes, in a computer system:

[0056] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the product item;

[0057] (b) generating, using the received indicating data, identity dataindicative of the identity of the product item;

[0058] (c) causing, using the identity data, provision of theassistance.

[0059] In another aspect the present invention provides a method ofproviding assistance relating to a product item, wherein the methodincludes providing the product item with an associated interfacesurface, the interface surface having disposed thereon or therein codeddata indicative of an identity of the product item such that when thecoded data portion is sensed by a sensing device, the sensing devicegenerates indicating data indicative of the product item identity, theindicating data being transferred to a computer system which isresponsive to the indicating data to cause provision of productassistance.

[0060] In a further aspect the present invention provides a sensingdevice for use in requesting assistance relating to a product item, theproduct item including an associated interface surface, the interfacesurface having disposed thereon or therein coded data indicative of anidentity of the product item, the sensing device including:

[0061] (a) a sensor for sensing the coded data;

[0062] (b) a processor for generating indicating data indicative of theproduct item identity; and,

[0063] (c) a communication means for transferring the indicating data toa computer system, the computer system being responsive to theindicating data to cause provision of product assistance.

[0064] In a further aspect the present invention provides a computersystem for providing assistance relating to a product item, the productitem including an associated interface surface, the interface surfacehaving disposed thereon or therein coded data indicative of an identityof the product item, wherein the computer system:

[0065] (a) receives indicating data generated by a sensing device inresponse to sensing of the coded data, the indicating data beingindicative of the product item identity;

[0066] (b) generates, using the received indicating data, identity dataindicative of the identity of the product item;

[0067] (c) causes, using the identity data, provision of the assistance.

[0068] In a further aspect the present invention provides a productitem, the product item having an associated interface surface, theinterface surface having disposed thereon or therein coded dataindicative of an identity of the product item such that when the codeddata portion is sensed by a sensing device, the sensing device generatesindicating data indicative of the product item identity, the indicatingdata being transferred to a computer system which is responsive to theindicating data to cause provide product related assistance.

[0069] In a second aspect the present invention provides a method ofmaintaining a status of a product item, the product item including anassociated interface surface, the interface surface having disposedthereon or therein coded data including a plurality of coded dataportions, each coded data portion being indicative of an identity of theproduct item, the method including, in a sensing device:

[0070] (a) sensing at least one coded data portion;

[0071] (b) generating, using the sensed coded data portion, indicatingdata indicative of the product item identity; and,

[0072] (c) transferring the indicating data to a computer system, thecomputer system being responsive to the indicating data to updateproduct status information stored in a data store.

[0073] In a further aspect the present invention provides a method ofmaintaining a status of a product item, the product item including anassociated interface surface, the interface surface having disposedthereon or therein coded data including a number of coded data portions,each coded data portion being indicative of an identity of the productitem, the method including, in a computer system:

[0074] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the product item;

[0075] (b) generating, using the received indicating data, identity dataindicative of the identity of the product item;

[0076] (c) update product status information stored in a data store.

[0077] In a further aspect the present invention provides a method ofmaintaining a status of a product item, wherein the method includesproviding the product item with an associated interface surface, theinterface surface having disposed thereon or therein coded dataincluding a plurality of coded data portions, each coded data portionbeing indicative of an identity of the product item such that when thecoded data portion is sensed by a sensing device, the sensing devicegenerates indicating data indicative of the product item identity, theindicating data being transferred to a computer system which isresponsive to the indicating data to update product status informationstored in a data store.

[0078] In a further aspect the present invention provides a sensingdevice for maintaining a status of a product item, the product itemincluding an associated interface surface, the interface surface havingdisposed thereon or therein coded data including a plurality of codeddata portions, each coded data portion being indicative of an identityof the product item, the sensing device including:

[0079] (a) a sensor for sensing at least one coded data portion;

[0080] (b) a processor for generating indicating data indicative of theproduct item identity; and,

[0081] (c) a communication means for transferring the indicating data toa computer system, the computer system being responsive to theindicating data to update product status information stored in a datastore.

[0082] In a further aspect the present invention provides a computersystem for providing status information relating to a product item, theproduct item including an associated interface surface, the interfacesurface having disposed thereon or therein coded data including aplurality of coded data portions, each coded data portion beingindicative of an identity of the product item, wherein the computersystem:

[0083] (a) receives indicating data generated by a sensing device inresponse to sensing of at least one coded data portion, the indicatingdata being indicative of the product item identity;

[0084] (b) generates, using the received indicating data, identity dataindicative of the identity of the product item; and,

[0085] (c) updates, using the identity data, the product statusinformation stored in a data store.

[0086] In a further aspect the present invention provides a productitem, the product item having an associated interface surface, theinterface surface having disposed thereon or therein coded dataincluding a plurality of coded data portions, each coded data portionbeing indicative of an identity of the product item such that when thecoded data portion is sensed by a sensing device, the sensing devicegenerates indicating data indicative of the product item identity, theindicating data being transferred to a computer system which isresponsive to the indicating data to update product status informationstored in a data store.

[0087] In a third aspect the present invention provides coded data fordisposal on or in an interface surface associated with a product item,wherein the coded data includes a plurality of coded data portionsdisposed on or in the interface surface, and wherein each coded dataportion is indicative of an identity of the product item such thatsensing any one of the coded data portions allows the identity of theproduct item to be determined.

[0088] In a further aspect the present invention provides an interfacesurface for use with a product item, the interface surface includingcoded data including a plurality of coded data portions disposed on orin the interface surface, and wherein each coded data portion isindicative of an identity of the product item such that sensing any oneof the coded data portions allows the identity of the product item to bedetermined.

[0089] In a fourth aspect the present invention provides coded data fordisposal on or in an interface surface associated with a product item,the coded data being indicative of an identity of the product item, thecoded data being arranged in accordance with at least one layout havingn-fold rotational symmetry about a center of rotation, where n is atleast two, the layout including n identical sub-layouts rotated 1/nrevolutions apart about the center of rotation, at least one sub-layoutincluding rotation-indicating data that distinguishes that sub-layoutfrom each other sub-layout.

[0090] In a further aspect the present invention provides an interfacesurface for use with a product item, the interface surface includingcoded data disposed thereon or therein, the coded data being indicativeof an identity of the product item, the coded data being arranged inaccordance with at least one layout having n-fold rotational symmetryabout a center of rotation, where n is at least two, the layoutincluding n identical sub-layouts rotated 1/n revolutions apart aboutthe center of rotation, at least one sub-layout includingrotation-indicating data that distinguishes that sub-layout from eachother sub-layout.

[0091] In a fifth aspect the present invention provides a method ofdetermining an orientation of a respective object, the object having aninterface surface having coded data disposed thereon or therein, whereinthe coded data includes a plurality of coded data portions provided atrespective positions on the interface surface, each coded data portionbeing indicative of an identity of the object, and wherein the methodincludes, in a sensing device:

[0092] (a) sensing at least one coded data portion;

[0093] (b) generating, using the sensed coded data portion, indicatingdata indicative of the object identity and at least one of:

[0094] (i) a position of the sensed coded data portion;

[0095] (ii) a position of the sensing device relative to the interfacesurface;

[0096] (iii) an orientation of the sensed coded data; and,

[0097] (iv) an orientation of the sensing device relative to theinterface surface; and,

[0098] (c) transferring the indicating data to a computer system, thecomputer system being responsive to the indicating data to determine theorientation of the object.

[0099] In a further aspect the present invention provides a method ofdetermining an orientation of a respective object, the object having aninterface surface having coded data disposed thereon or therein, whereinthe coded data includes a plurality of coded data portions provided atrespective positions on the interface surface, each coded data portionbeing indicative of an identity of the object, and wherein the methodincludes, in a sensing device:

[0100] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the object and at leastone of:

[0101] (i) a position of the sensing device with respect to theinterface surface;

[0102] (ii) a position of the sensed coded data;

[0103] (iii) an orientation of the sensed coded data; and,

[0104] (iv) an orientation of the sensing device relative to theinterface surface.

[0105] (b) generating, using the received indicating data:

[0106] (i) , identity data indicative of the object identity; and,

[0107] (ii) position data indicative of at least one of:

[0108] (1) the position of the sensed coded data portion; and,

[0109] (2) a position of the sensing device relative to the interfacesurface; and,

[0110] (c) determining, using the identity data and the position data,orientation of the object.

[0111] In a further aspect the present invention provides a method ofdetermining an orientation of a respective object, the object having aninterface surface having coded data disposed thereon or therein, whereinthe interface surface includes at least one region having at least onecoded data portion provided therein, the at least one coded data portionbeing indicative of an identity of the region, and wherein the methodincludes, in a sensing device:

[0112] (a) sensing at least one coded data portion;

[0113] (b) generating, using the sensed coded data portion, indicatingdata indicative of the region identity; and,

[0114] (c) transferring the indicating data to a computer system, thecomputer system being responsive to the indicating data to determine theorientation of the object.

[0115] In a further aspect the present invention provides a method ofdetermining the orientation of a respective object, the object having aninterface surface having coded data disposed thereon or therein, whereinthe interface surface includes at least one region having at least onecoded data portion provided therein, the at least one coded data portionbeing indicative of an identity of the region, and wherein the methodincludes, in a computer system:

[0116] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the region:

[0117] (b) determining, using the indicating data, region identity dataindicative of the identity of the region; and,

[0118] (c) determining, using the region identity data, the orientationof the object.

[0119] In a sixth aspect the present invention provides a method ofpacking an object, the object having an interface surface having codeddata disposed thereon or therein, wherein the coded data includes aplurality of coded data portions, each coded data portion beingindicative of an identity of the object, wherein the method includes, ina sensing device:

[0120] (a) sensing at least one coded data portion;

[0121] (b) generating, using the sensed coded data portion, indicatingdata indicative of the identity of the object; and,

[0122] (c) transferring the indicating data to at least one of:

[0123] (i) a packing system which is responsive to the indication topack the object.

[0124] (ii) a computer system which is responsive to the indication tocause a packing system to pack the object.

[0125] In a further aspect the present invention provides a method ofpacking an object, the object having an interface surface having codeddata disposed thereon or therein, wherein the coded data includes aplurality of coded data portions, each coded data portion beingindicative of an identity of the object, wherein the method includes, ina packing system:

[0126] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the object;

[0127] (b) generating, using the received indicating data, objectidentity data indicative of the identity of the object; and,

[0128] (c) packing the object using the object identity data.

[0129] In a further aspect the present invention provides a method ofpacking an object, the object having an interface surface having codeddata disposed thereon or therein, wherein the coded data includes aplurality of coded data portions, each coded data portion beingindicative of an identity of the object, wherein the method includes:

[0130] (a) in a sensing device:

[0131] (i) sensing at least one coded data portion;

[0132] (ii) generating, using the sensed coded data portion, indicatingdata indicative of the identity of the object; and,

[0133] (iii) transferring the indicating data to a packing system; and,

[0134] (b) in the packing system;

[0135] (i) receiving the indicating data;

[0136] (ii) generating, using the received indicating data, objectidentity data indicative of the identity of the object; and,

[0137] (iii) packing the object using the object identity data.

[0138] In a further aspect the present invention provides a method ofpacking an object, the object having an interface surface having codeddata disposed thereon or therein, wherein the coded data includes aplurality of coded data portions, each coded data portion beingindicative of an identity of the object, wherein the method includes, ina computer system:

[0139] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the object;

[0140] (b) generating, using the received indicating data, objectidentity data indicative of the identity of the object; and,

[0141] (c) causing, using the object identity data, a packing system topack the object.

[0142] In a further aspect the present invention provides a method ofpacking an object, the object having an interface surface having codeddata disposed thereon or therein, wherein the coded data includes aplurality of coded data portions, each coded data portion beingindicative of an identity of the object, wherein the method includes:

[0143] (a) in a sensing device:

[0144] (i) sensing at least one coded data portion;

[0145] (ii) generating, using the sensed coded data portion, indicatingdata indicative of the identity of the object; and,

[0146] (iii) transferring the indicating data to a computer system; and,

[0147] (b) in the computer system;

[0148] (i) receiving the indicating data; and,

[0149] (ii) generating, using the received indicating data, objectidentity data indicative of the identity of the object; and,

[0150] (iii) causing, using the object identity data, a packing systemto pack the object.

[0151] In a further aspect the present invention provides a system forpacking an object, the object having an interface surface having codeddata disposed thereon or therein, wherein the coded data includes aplurality of coded data portions, each coded data portion beingindicative of an identity of the object, wherein the system includes asensing device which:

[0152] (a) senses at least one coded data portion;

[0153] (b) generates, using the sensed coded data portion, indicatingdata indicative of the identity of the object; and,

[0154] (c) transfers the indicating data to a packing system which isresponsive to the indication to pack the object.

[0155] In a further aspect the present invention provides a system forpacking a object, the object having an interface surface having codeddata disposed thereon or therein, wherein the coded data includes aplurality of coded data portions, each coded data portion beingindicative of an identity of the object and the position of the codeddata portion on the interface surface, wherein the system includes apacking system which:

[0156] (a) receives, from a sensing device, indicating data generated inresponse to sensing of a coded data portion, the indicating data beingindicative of the object identity;

[0157] (b) generates, from the received indicating data, object identitydata indicative of the identity of the object; and,

[0158] (c) packs the object using the object identity data.

[0159] In a further aspect the present invention provides a system forpacking a object, the object having an interface surface having codeddata disposed thereon or therein, wherein the coded data includes aplurality of coded data portions, each coded data portion beingindicative of an identity of the object and the position of the codeddata portion on the interface surface, wherein the system includes acomputer system which:

[0160] (a) receives, from a sensing device, indicating data generated inresponse to sensing of a coded data portion, the indicating data beingindicative of the object identity;

[0161] (b) generates, from the received indicating data, object identitydata indicative of the identity of the object; and,

[0162] (c) causes, using the object identity data, a packing system topack the object.

[0163] In a seventh aspect the present invention provides a method ofassembling an object using a component, the component having aninterface surface having coded data disposed thereon or therein, eachcoded data portion being indicative of an identity of the component,wherein the method includes, in a sensing device:

[0164] (a) sensing coded data on the component;

[0165] (b) generating, using the sensed coded data, indicating dataindicative of the identity of the component; and,

[0166] (c) transferring the indicating data to at least one of:

[0167] (i) an assembly system which is responsive to the indication toassemble the object; and,

[0168] (ii) a computer system which is responsive to the indication tocause an assembly system to assemble the object.

[0169] In a further aspect the present invention provides a method ofassembling an object using a component, the component having aninterface surface having coded data disposed thereon or therein, eachcoded data portion being indicative of an identity of the component,wherein the method includes, in an assembly system:

[0170] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the component;

[0171] (b) generating, using the received indicating data, componentidentity data indicative of the identity of the component; and,

[0172] (c) assembling the object using the component identity data.

[0173] In a further aspect the present invention provides a method ofassembling an object, the component having an interface surface havingcoded data disposed thereon or therein, wherein the coded data includesa plurality of coded data portions, each coded data portion beingindicative of an identity of the component, wherein the method includes:

[0174] (a) in a sensing device:

[0175] (i) sensing at least one coded data portion;

[0176] (ii) generating, using the sensed coded data portion, indicatingdata indicative of the identity of the component; and,

[0177] (iii) transferring the indicating data to an assembly system;and,

[0178] (b) in the assembly system;

[0179] (i) receiving the indicating data;

[0180] (ii) generating, using the received indicating data componentidentity data indicative of the identity of the component; and,

[0181] (iii) assembling the object using the component identity data.

[0182] In a further aspect the present invention provides a method ofassembling an object, the component having an interface surface havingcoded data disposed thereon or therein, wherein the coded data includesa plurality of coded data portions, each coded data portion beingindicative of an identity of the component, wherein the method includes:

[0183] (a) in a sensing device:

[0184] (i) sensing at least one coded data portion;

[0185] (ii) generating, using the sensed coded data portion, indicatingdata indicative of the identity of the component; and,

[0186] (iii) transferring the indicating data to a computer system; and,

[0187] (b) in the computer system;

[0188] (i) receiving the indicating data;

[0189] (ii) generating, using the received indicating data, componentidentity data indicative of the identity of the component; and,

[0190] (iii) causing, using the component identity data, an assemblysystem to assemble the object.

[0191] In a further aspect the present invention provides a method ofassembling an object using a component, the component having aninterface surface having coded data disposed thereon or therein, eachcoded data portion being indicative of an identity of the component,wherein the method includes, in a computer system:

[0192] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the component;

[0193] (b) generating, using the received indicating data, componentidentity data indicative of the identity of the component; and,

[0194] (c) causing, using the component identity data, an assemblysystem to assemble the object.

[0195] In a further aspect the present invention provides a system forassembling an object using a component, the component having aninterface surface having coded data disposed thereon or therein, whereinthe coded data includes a plurality of coded data portions, each codeddata portion being indicative of an identity of the component, whereinthe system includes a sensing device which:

[0196] (a) senses at least one coded data portion;

[0197] (b) generates, using the sensed coded data portion, indicatingdata indicative of the identity of the component; and,

[0198] (c) transfers the indicating data to at least one of:

[0199] (i) an assembly system which is responsive to the indication toassemble the object; and,

[0200] (ii) a computer system which is responsive to the indication tocause an assembly system to assemble the object.

[0201] In a further aspect the present invention provides a system forassembling an object using a component, the component having aninterface surface having coded data disposed thereon or therein, whereinthe coded data includes a plurality of coded data portions, each codeddata portion being indicative of an identity of the component and theposition of the coded data portion on the interface surface, wherein thesystem includes an assembly system which:

[0202] (a) receives, from a sensing device, indicating data generated inresponse to sensing of a coded data portion, the indicating data beingindicative of the component identity;

[0203] (b) generates, from the received indicating data, componentidentity data indicative of the identity of the component; and,

[0204] (c) assembles the object using the component identity data.

[0205] In a further aspect the present invention provides a system forassembling an object using a component, the component having aninterface surface having coded data disposed thereon or therein, whereinthe coded data includes a plurality of coded data portions, each codeddata portion being indicative of an identity of the component and theposition of the coded data portion on the interface surface, wherein thesystem includes a computer system which:

[0206] (a) receives, from a sensing device, indicating data generated inresponse to sensing of a coded data portion, the indicating data beingindicative of the component identity;

[0207] (b) generates, from the received indicating data, componentidentity data indicative of the identity of the component; and,

[0208] (c) causes, using the component identity data, an assembly systemto assemble the object.

[0209] In an eighth aspect the present invention provides a method ofidentifying a face of an object, the object having a plurality of faces,each face having coded data disposed thereon or therein, wherein thecoded data includes a plurality of coded data portions provided atrespective positions on each face, each coded data portion beingindicative of an identity of the object, and wherein the methodincludes, in a sensing device:

[0210] (a) sensing at least one coded data portion;

[0211] (b) generating, using the sensed coded data portion, indicatingdata indicative of the object identity and at least one of:

[0212] (i) a position of the sensed coded data portion;

[0213] (ii) a position of the sensing device relative to the face;

[0214] (iii) an orientation of the sensed coded data; and,

[0215] (iv) an orientation of the sensing device relative to the face;and,

[0216] (c) transferring the indicating data to a computer system, thecomputer system being responsive to the indicating data to identify theface.

[0217] In a further aspect the present invention provides a method ofidentifying a face of an object, the object having a plurality of faces,each face having coded data disposed thereon or therein, wherein thecoded data includes a plurality of coded data portions provided atrespective positions on each face, each coded data portion beingindicative of an identity of the object, and wherein the methodincludes, in a computer system:

[0218] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the object and at leastone of:

[0219] (i) a position of the sensed coded data portion;

[0220] (ii) a position of the sensing device relative to the face;

[0221] (iii) an orientation of the sensed coded data; and,

[0222] (iv) an orientation of the sensing device relative to the face;and,

[0223] (b) generating, using the received indicating data:

[0224] (i) identity data indicative of the object identity; and,

[0225] (ii) position data indicative of at least one of:

[0226] (1) the position of the sensed coded data portion;

[0227] (2) the position of the sensing device relative to the face;

[0228] (3) the orientation of the sensed coded data; and,

[0229] (4) the orientation of the sensing device relative to the face;and,

[0230] (c) identifying, using the identity data and the position data,the face.

[0231] In a further aspect the present invention provides a method ofidentifying a face of an object, the object having a plurality of faces,each face having coded data disposed thereon or therein, each facehaving at least one region having at least one coded data portionprovided therein, the at least one coded data portion being indicativeof an identity of the region, and wherein the method includes, in asensing device:

[0232] (a) sensing at least one coded data portion;

[0233] (b) generating, using the sensed coded data portion, indicatingdata indicative of the region identity; and,

[0234] (c) transferring the indicating data to a computer system, thecomputer system being responsive to the indicating data to determine theface.

[0235] In a further aspect the present invention provides a method ofidentifying a face of an object, the object having a surface havingcoded data disposed thereon or therein, wherein the face includes atleast one region having at least one coded data portion providedtherein, the at least one coded data portion being indicative of anidentity of the region, and wherein the method includes, in a computersystem:

[0236] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the region:

[0237] (b) generating, using the indicating data, region identity dataindicative of the identity of the region; and,

[0238] (c) identifying, using the region identity data, the orientationof the object.

[0239] In a ninth aspect the present invention provides a method offacilitating communications using a product item, the product itemincluding an associated interface surface, the interface surface havingdisposed thereon or therein coded data indicative of an identity of theproduct item, the method including, in a sensing device:

[0240] (a) sensing at least some of the coded data;

[0241] (b) generating, using the sensed coded data, indicating dataindicative of the product item identity; and,

[0242] (c) transferring the indicating data to a computer system, thecomputer system being responsive to the indicating data to facilitatecommunications.

[0243] In a further aspect the present invention provides a method offacilitating communications using a product item, the product itemincluding an associated interface surface, the interface surface havingdisposed thereon or therein coded data indicative of an identity of theproduct item, the method including, in a computer system:

[0244] (a) receiving indicating data from a sensing device, the sensingdevice being responsive to sensing of the coded data to generateindicating data indicative of the identity of the product item;

[0245] (b) generating, using the received indicating data, identity dataindicative of the product item identity; and,

[0246] (c) facilitating communications using the product item identity.

[0247] In a further aspect the present invention provides a method offacilitating communications relating to a product item, wherein themethod includes providing the product item with an associated interfacesurface, the interface surface having disposed thereon or therein codeddata indicative of an identity of the product item such that when thecoded data portion is sensed by a sensing device, the sensing devicegenerates indicating data indicative of the product item identity, theindicating data being transferred to a computer system which isresponsive to the indicating data to facilitate communications.

[0248] In a tenth aspect the present invention provides a sensing devicefor sensing a product item provided in a sensing region, wherein theproduct item includes an interface surface having disposed thereon atleast one of:

[0249] (a) coded data which includes, at a plurality of locations on theinterface surface, a corresponding plurality of coded data portions,each coded data portion being indicative of an identity of the productitem; and,

[0250] (b) a barcode which encodes an identifier;

[0251] the sensing device including:

[0252] (i) a coded data sensor for sensing at least one coded dataportion;

[0253] (ii) a barcode sensor for sensing the barcode;

[0254] (iii) a processor for generating identity data indicative of theidentity of the product item using at least one of:

[0255] (1) the at least one sensed coded data portion; and,

[0256] (2) the barcode;

[0257] (c) a communicator for transferring the indicating data to acomputer system.

[0258] In a further aspect the present invention provides a sensingdevice adapted to scan a product item provided in a sensing region,wherein the product item includes an interface surface having disposedthereon at least one of:

[0259] (a) coded data which includes, at a plurality of locations on theinterface surface, a corresponding plurality of coded data portions,each coded data portion being indicative of an identity of the productitem, the product item being provided in a sensing region; and,

[0260] (b) an RFID tag which encodes an identifier; and, the sensingdevice including:

[0261] (i) a coded data sensor for sensing at least one coded dataportion;

[0262] (ii) a RFID tag reader for reading RFID tags;

[0263] (iii) a processor for determining indicating data using at leastone of:

[0264] (1) the identity of the product item determined from at least onesensed coded data portion; and,

[0265] (2) the identifier determined using the RFID tag reader;

[0266] (c) a communicator for transferring the indicating data to acomputer system.

[0267] In an eleventh aspect the present invention provides a method offacilitating interaction between a user and a computer system using aproduct item having an interface surface, the interface surface havingdisposed thereon or therein coded data including a plurality of codeddata portions, each coded data portion being indicative of an identityof the product item, the interaction being mediated by a sensing device,wherein the method includes:

[0268] (a) associating the sensing device with the user;

[0269] (b) in the sensing device:

[0270] (i) sensing at least one coded data portion when the sensingdevice is placed in an operative position relative to the interfacesurface; and

[0271] (ii) generating, using at least some of the sensed coded data,indicating data indicative of the identity of the product item and anidentity of the sensing device; and,

[0272] (iii) transferring the indicating data to a computer system;

[0273] (c) in the computer system:

[0274] (i) receiving the indicating data;

[0275] (ii) generating, using the received indicating data:

[0276] (1) product identity data indicative of the identity of theproduct item;

[0277] (2) sensing device identity data indicative of the identity ofthe sensing device; and,

[0278] (d) dissociating the sensing device and the user.

[0279] In a further aspect the present invention provides a method offacilitating interaction between a user and a computer system using aproduct item having an interface surface, the interface surface havingdisposed thereon or therein coded data including a plurality of codeddata portions, each coded data portion being indicative of an identityof the product item, the interaction being performed by a sensingdevice, wherein the method includes:

[0280] (a) associating the sensing device with the user;

[0281] (b) in a computer system:

[0282] (i) receiving indicating data generated by the sensing device inresponse to sensing at least one coded data portion, the indicating databeing indicative of the identity of the product item;

[0283] (ii) generating, using the received indicating data:

[0284] (1) product identity data indicative of the identity of theproduct item;

[0285] (2) sensing device identity data indicative of an identity of thesensing device; and,

[0286] (c) facilitating the interaction using the product identity dataand the sensing device identity data.

[0287] In a twelfth aspect the present invention provides a shoppingreceptacle, the shopping receptacle being adapted to receive and retaina product item, the product item having an interface surface associatedtherewith, the interface surface having disposed thereon or thereincoded data including a plurality of coded data portions, each coded dataportion being indicative of an identity of the product item, wherein thereceptacle comprises:

[0288] (a) a receptacle body adapted to receive and retain the productitem and having an opening through which the product item may be placedwithin the receptacle body; and,

[0289] (b) a sensing device adapted to:

[0290] (i) emit at least one scanning beam across the opening of thereceptacle body;

[0291] (ii) sense at least one coded data portion on the interfacesurface of the product item as the product item is positioned in thereceptacle opening; and

[0292] (iii) generate, using the at least one sensed coded data portion,indicating data indicative of the identity of the product item.

[0293] In a further aspect the present invention provides a method offacilitating interaction between a user and a computer system using ashopping receptacle adapted to receive and retain a product item, theproduct item having an interface surface associated therewith, theinterface surface having disposed thereon or therein coded dataincluding a plurality of coded data portions, each coded data portionbeing indicative of the identity of the product item, wherein the methodincludes:

[0294] (a) positioning the product item in an opening of a receptaclebody which is adapted to receive and retain the product item; and,

[0295] (b) in a sensing device:

[0296] (i) sensing at least one coded data portion on the interfacesurface of the product item as the product item is positioned in thereceptacle opening; and

[0297] (ii) generating, using the at least one sensed coded dataportion, indicating data indicative of the identity of the product item;and,

[0298] (iii) transferring the indicating data to a computer system.

[0299] In a thirteenth aspect the present invention provides a shoppingreceptacle for facilitating interaction between a user and a computersystem, the receptacle being adapted to receive and retain a productitem having an interface surface associated therewith, the interfacesurface having disposed thereon or therein coded data including aplurality of coded data portions, each coded data portion beingindicative of the identity of the product item, wherein the receptaclecomprises:

[0300] (a) a receptacle body adapted to receive and retain the productitem; and,

[0301] (b) a sensing device adapted to:

[0302] (i) sense at least some of the coded data on the interfacesurface of the product item as the product item is positioned in asensing region; and,

[0303] (ii) generate, using the sensed coded data, indicating dataindicative of the identity of the product item; and,

[0304] (iii) transfer the indicating data to the computer system; and,

[0305] (c) a user interface for facilitating the interaction with thecomputer system, the interaction being performed using the indicatingdata.

[0306] In a further aspect the present invention provides a method offacilitating interaction between a user and a computer system using ashopping receptacle adapted to receive and retain a product item, theproduct item having an interface surface associated therewith, theinterface surface having disposed thereon or thereon coded dataincluding a plurality of coded data portions, each coded data portionbeing indicative of the identity of the product item, wherein the methodincludes:

[0307] (a) positioning the product item in a sensing region;

[0308] (b) in a sensing device:

[0309] (i) sensing at least some of the coded data on the interfacesurface of the product item as the product item is positioned in asensing region; and,

[0310] (ii) generating, using the sensed coded data, indicating dataindicative of the identity of the product item; and,

[0311] (c) in a user interface, facilitating interaction in accordancewith the indicating data.

[0312] In a fourteenth aspect the present invention provides a shoppingreceptacle for receiving and retaining a product item having aninterface surface associated therewith, the interface surface havingdisposed thereon or therein coded data including a plurality of codeddata portions, each coded data portion being indicative of an identityof the product item, wherein the receptacle comprises:

[0313] (a) a receptacle body adapted to receive and retain the productitem and having an opening through which the product item may be placedwithin the receptacle body;

[0314] (b) a sensing device adapted to sense at least some of the codeddata on the interface surface of the product item as the product item isplaced within the receptacle body, and generate indicating dataindicative of the identity of the product item; and,

[0315] (c) a weighing device for sensing the weight of the product item,and generating weight data indicative of the sensed weight, the weightdata and the product item identity being provided to a computer systemwhich:

[0316] (i) determines, using the indicating data, an indicated weight ofthe product item in accordance with weight indications stored in a datastore;

[0317] (ii) compares the indicated weight to the sensed weight; and,

[0318] (iii) is responsive to the comparison.

[0319] In a further aspect the present invention provides a method offacilitating interaction between a user and a computer system using ashopping receptacle adapted to receive and retain a product item, theproduct item having an interface surface associated therewith, theinterface surface having disposed thereon or therein coded dataincluding a plurality of coded data portions, each coded data portionbeing indicative of the identity of the product item, wherein the methodincludes:

[0320] (a) receiving a product item in a receptacle body, the receptaclebody having an opening through which the product item may be placedwithin the receptacle body;

[0321] (b) in a sensing device:

[0322] (i) sensing at least some of the coded data on the interfacesurface of the product item as the product item is placed within thereceptacle body; and,

[0323] (ii) determining indicating data indicative of the identity ofthe product item; and,

[0324] (c) in a weighing device:

[0325] (i) sensing the weight of the product item; and,

[0326] (ii) generating weight data indicative of the sensed weight, theweight data and the product item identity being provided to a computersystem which:

[0327] (1) determines, using the indicating data, an indicated weight ofthe product item in accordance with weight indications stored in a datastore;

[0328] (2) compares the indicated weight to the sensed weight; and,

[0329] (3) is responsive to the comparison to perform an action.

[0330] In a fifteenth aspect the present invention provides a card foridentifying a user to a computer system using a sensing device, the cardhaving an interface surface having disposed thereon or therein codeddata, the coded data including a plurality of coded data portions, eachcoded data portion being indicative of an identity of the user, thesensing device being adapted to:

[0331] (a) sense at least one coded data portion;

[0332] (b) generate, using the at least one sensed coded data portion,indicating data indicative of the identity of the user; and,

[0333] (c) transfer the indicating data to the computer system, thecomputer system being responsive to determine, using the indicatingdata, the identity of the user.

[0334] In a further aspect the present invention provides a method ofusing a card for facilitating interaction between a user and a computersystem, the card having an interface surface having disposed thereon ortherein coded data, the coded data including a plurality of coded dataportions, each coded data portion being indicative of an identity of theuser, wherein the method includes in a sensing device:

[0335] (a) sensing at least one coded data portion when the sensingdevice is placed in an operative position relative to the interfacesurface;

[0336] (b) generating, using the at least one sensed coded data portion,indicating data indicative of the identity of the user; and,

[0337] (c) transferring the indicating data to the computer system, thecomputer system being responsive to the indicating data to perform anaction.

[0338] In a further aspect the present invention provides a method ofcreating a card for facilitating interaction between a user and acomputer system, the method including, in a computer system:

[0339] (a) receiving information indicative of an identity of the user;

[0340] (b) generating at least one coded data portion indicative of theidentity of the user; and,

[0341] (c) disposing coded data on an interface surface of the card, thecoded data including a plurality of the coded data portions disposed tothereby allow the identity of the user to be determined by sensing anyone of the data portions with a sensing device.

[0342] In a sixteenth aspect the present invention provides a method ofprinting an interface surface associated with a product item, the methodincluding in a computer system:

[0343] (a) determining product identity data indicative of an identityof the product item; and,

[0344] (b) controlling a printer to thereby print a plurality of codeddata portions on the interface surface, each coded data portion beingindicative of the product identity data such the product identity datacan be determined by sensing any one of the coded data portions with asensing device.

[0345] In a further aspect the present invention provides a method ofindicating an identity of a product item, the method including:

[0346] (a) determining indicating data indicative of an identity of theproduct item;

[0347] (b) determining, using the indicating data, at least one codeddata portion indicative of the identity of the product item; and,

[0348] (c) determining, using the indicating data, at least one barcodeindicative of the identity of the product item; and,

[0349] (d) printing, on an interface surface associated with the productitem:

[0350] (i) a plurality of coded data portions on the interface surface,each coded data portion being indicative of the product identity datasuch that the product identity data can be determined by sensing any oneof the coded data portions with a sensing device; and,

[0351] (ii) the barcode.

[0352] In a further aspect the present invention provides a method ofindicating an identity of a product item, the method including:

[0353] (a) determining indicating data indicative of an identity of theproduct item;

[0354] (b) determining, using the indicating data, at least one codeddata portion indicative of the identity of the product item; and,

[0355] (c) determining, using the indicating data, at least one barcodeindicative of the identity of the product item; and,

[0356] (d) printing, on an interface surface associated with the productitem, a plurality of coded data portions, each coded data portion beingindicative of the product identity data such the product identity datacan be determined by sensing any one of the coded data portions with asensing device; and,

[0357] (e) encoding the product identity data in an RFID tag.

[0358] In a further aspect the present invention provides a printer forprinting an interface surface associated with a product item, theprinter being adapted to print a plurality of coded data portions on theinterface surface, each coded data portion being indicative of productidentity data, and the product identity data being indicative of anidentity of the product item, such that the product identity data can bedetermined by sensing any one of the coded data portions with a sensingdevice.

[0359] In a further aspect the present invention provides a system forprinting an interface surface associated with a product item, the systemincluding:

[0360] (f) a computer system for:

[0361] (i) receiving indicating data indicative of an identity of theproduct item; and,

[0362] (ii) generating, using the indicating data, product identity dataindicative of the identity of the product item; and,

[0363] (g) a printing system for printing a plurality of coded dataportions on the interface surface, each coded data portion beingindicative of the product identity data such the product identity datacan be determined by sensing any one of the coded data portions with asensing device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0364] Preferred and other embodiments of the invention will now bedescribed, by way of non-limiting example only, with reference to theaccompanying drawings, in which:

[0365]FIG. 1 is a schematic of a the relationship between a sampleprinted netpage and its online page description;

[0366]FIG. 2 is a schematic view of a interaction between a netpage pen,a Web terminal, a netpage printer, a netpage relay, a netpage pageserver, and a netpage application server, and a Web server;

[0367]FIG. 3 illustrates a collection of netpage servers, Web terminals,printers and relays interconnected via a network;

[0368]FIG. 4 is a schematic view of a high-level structure of a printednetpage and its online page description;

[0369]FIG. 5a is a plan view showing the interleaving and rotation ofthe symbols of four codewords of the tag;

[0370]FIG. 5b is a plan view showing a macrodot layout for the tag shownin FIG. 5a;

[0371]FIG. 5c is a plan view showing an arrangement of nine of the tagsshown in FIGS. 5a and 5b, in which targets are shared between adjacenttags;

[0372]FIG. 6 is a plan view showing a relationship between a set of thetags shown in FIG. 6a and a field of view of a netpage sensing device inthe form of a netpage pen;

[0373]FIG. 7 is a flowchart of a tag image processing and decodingalgorithm;

[0374]FIG. 8 is a perspective view of a netpage pen and its associatedtag-sensing field-of-view cone;

[0375]FIG. 9 is a perspective exploded view of the netpage pen shown inFIG. 8;

[0376]FIG. 10 is a schematic block diagram of a pen controller for thenetpage pen shown in FIGS. 8 and 9;

[0377]FIG. 11 is a perspective view of a wall-mounted netpage printer;

[0378]FIG. 12 is a section through the length of the netpage printer ofFIG. 11;

[0379]FIG. 12a is an enlarged portion of FIG. 12 showing a section ofthe duplexed print engines and glue wheel assembly;

[0380]FIG. 13 is a detailed view of the ink cartridge, ink, air and gluepaths, and print engines of the netpage printer of FIGS. 11 and 12;

[0381]FIG. 14 is a schematic block diagram of a printer controller forthe netpage printer shown in FIGS. 11 and 12;

[0382]FIG. 15 is a schematic block diagram of duplexed print enginecontrollers and Memjet™ printheads associated with the printercontroller shown in FIG. 14;

[0383]FIG. 16 is a schematic block diagram of the print enginecontroller shown in FIGS. 14 and 15;

[0384]FIG. 17 is a perspective view of a single Memjet™ printingelement, as used in, for example, the netpage printer of FIGS. 10 to 12;

[0385]FIG. 18 is a schematic view of the structure of an item ID;

[0386]FIG. 19 is a schematic view of the structure of a Hyperlabel™ tag;

[0387]FIG. 20 is a schematic view of a product item and object ownershipand packaging hierarchy class diagram;

[0388]FIG. 21 is a schematic view of a user class diagram;

[0389]FIG. 22 is a schematic view of a printer class diagram;

[0390]FIG. 23 is a schematic view of a pen class diagram;

[0391]FIG. 24 is a schematic view of an application class diagram;

[0392]FIG. 25 is a schematic view of a document and page descriptionclass diagram;

[0393]FIG. 26 is a schematic view of a document and page ownership classdiagram;

[0394]FIG. 27 is a schematic view of a terminal element specializationclass diagram;

[0395]FIG. 28 is a schematic view of a static element specializationclass diagram;

[0396]FIG. 29 is a schematic view of a hyperlink element class diagram;

[0397]FIG. 30 is a schematic view of a hyperlink element specializationclass diagram;

[0398]FIG. 31 is a schematic view of a hyperlinked group class diagram;

[0399]FIG. 32 is a schematic view of a form class diagram;

[0400]FIG. 33 is a schematic view of a digital ink class diagram;

[0401]FIG. 34 is a schematic view of a field element specializationclass diagram;

[0402]FIG. 35 is a schematic view of a checkbox field class diagram;

[0403]FIG. 36 is a schematic view of a text field class diagram;

[0404]FIG. 37 is a schematic view of a signature field class diagram;

[0405]FIG. 38 is a flowchart of an input processing algorithm;

[0406]FIG. 38a is a detailed flowchart of one step of the flowchart ofFIG. 38;

[0407]FIG. 39 is a schematic view of a page server command element classdiagram;

[0408]FIG. 40 is a schematic view of a subscription delivery protocol;

[0409]FIG. 41 is a schematic view of a hyperlink request class diagram;

[0410]FIG. 42 is a schematic view of a hyperlink activation protocol;

[0411]FIG. 43 is a schematic view of a form submission protocol;

[0412]FIG. 44 shows a triangular macrodot packing with a four-bit symbolunit outlined, for use with an embodiment of the invention;

[0413]FIG. 45 shows a square macrodot packing with a four-bit symbolunit outlined, for use with an embodiment of the invention such as thatdescribed in relation to FIGS. 5a to 5 c;

[0414]FIG. 46 shows a one-sixth segment of an hexagonal tag, with thesegment containing a maximum of 11 four-bit symbols with the triangularmacrodot packing shown in FIG. 44;

[0415]FIG. 47 shows a one-quarter segment of a square tag, with thesegment containing a maximum of 15 four-bit symbols with the squaremacrodot packing shown in FIG. 45;

[0416]FIG. 48 shows a logical layout of a hexagonal tag using the tagsegment of FIG. 47, with six interleaved 2⁴-ary (11, k) codewords;

[0417]FIG. 49 shows the macrodot layout of the hexagonal tag of FIG. 48;

[0418]FIG. 50 shows an arrangement of seven abutting tags of the designof FIGS. 48 and 49, with shared targets;

[0419]FIG. 51 shows a logical layout of an alternative hexagonal tagusing the tag segment of FIG. 47, with three interleaved 2⁴-ary (9, k)codewords and three interleaved three-symbol fragments of threedistributed 2⁴-ary (9, k) codewords;

[0420]FIG. 52 shows the logical layout of an orientation-indicatingcyclic position codeword of the hexagonal tag of FIG. 51;

[0421]FIG. 53 shows three adjacent tags of type P, Q and R, each withthe layout of the tag of FIG. 51, containing a complete set ofdistributed codewords;

[0422]FIG. 54 shows the logical layout of yet another alternativehexagonal tag using the tag segment of FIG. 47, with one local 2⁴-ary(12, k) codeword, interleaved with eighteen 3-symbol fragments ofeighteen distributed 2⁴-ary (9, k) codewords;

[0423]FIG. 55 shows the logical layout of the hexagonal tag of FIG. 54,re-arranged to show the distributed 3-symbol fragments which contributeto the same codewords;

[0424]FIG. 56 is a schematic view of a physical product item and itsonline description;

[0425]FIG. 57 is a schematic view of the interaction between a productitem, a fixed product scanner, a hand-held product scanner, a scannerrelay, a product server, and a product application server

[0426]FIG. 58 shows a plan and elevation view of a hand-held Hyperlabel™scanner 4000 according to a preferred embodiment of the presentinvention;

[0427]FIG. 59 shows a cross-sectional view A of the scanner of FIG. 58;

[0428]FIG. 60 shows a cross-sectional view B of the scanner of FIG. 58;

[0429]FIG. 61 shows an exploded view of the hand-held scanner;

[0430]FIG. 62 shows a view of the optical and electronic sub-assembliesof the hand-held scanner;

[0431]FIG. 63 shows a close-up view of the optical sub-assembly;

[0432]FIG. 64 shows an exploded view of the optical sub-assembly;

[0433]FIG. 65 shows a plan and elevation view of a netpage pen 3000according to a preferred embodiment of the present invention;

[0434]FIG. 66 shows a cross-sectional view A of the pen of FIG. 65;

[0435]FIG. 67 shows a cross-sectional view B of the pen of FIG. 65;

[0436]FIG. 68 shows a view of the optical and electronic sub-assembliesof the pen;

[0437]FIG. 69 shows a block diagram of salient aspects of theelectronics of the scanner and pen;

[0438]FIG. 70 shows a view of a glove Hyperlabel™ scanner 5000 accordingto a preferred embodiment of the present invention;

[0439]FIG. 71 is a schematic diagram of the optics of the glove scannerof FIG. 70;

[0440]FIG. 72 shows a plan and elevation view of a hand-held Hyperlabel™scanner 4200 according to a preferred embodiment of the presentinvention;

[0441]FIG. 73 shows a cross-sectional view A of the scanner of FIG. 72;

[0442]FIG. 74 shows a block diagram of salient aspects of theelectronics of the scanner and pen;

[0443]FIG. 75 shows the return light detection path of the scanner ofFIG. 72;

[0444]FIG. 76 shows a schematic of a first example of a fixedHyperlabel™ laser scanner 1500 according to a preferred embodiment ofthe present invention;

[0445]FIG. 77 shows the beam steering mirror of the scanner in a nominalposition;

[0446]FIG. 78 shows the beam steering mirror of the scanner in a “low”position;

[0447]FIG. 79 shows the beam steering mirror of the scanner in a “high”position;

[0448]FIG. 80 shows the beam steering mirror of the scanner selecting analternative deflection mirror;

[0449]FIG. 81 shows the return light detection path of the scanner;

[0450]FIG. 82 shows an elevation view of the scanner incorporated in thecheckout;

[0451]FIG. 83 shows a plan view of the scanner incorporated in thecheckout, showing beam paths below the conveyor;

[0452]FIG. 84 shows a plan view of the scanner incorporated in thecheckout, showing beam paths above the conveyor; and

[0453]FIG. 85 shows a block diagram of salient aspects of theelectronics of the scanner FIG. 76; and,

[0454]FIG. 86 shows a schematic of a second example of a fixedHyperlabel™ laser scanner 1500 according to a preferred embodiment ofthe present invention;

[0455]FIG. 87 shows a schematic of a third example of a fixedHyperlabel™ laser scanner 1500 according to a preferred embodiment ofthe present invention;

[0456]FIG. 88 shows a view of a first example of a checkout 1000incorporating a fixed Hyperlabel™ laser scanner 1500, both according topreferred embodiments of the present invention;

[0457]FIG. 89 shows a plan view of the checkout of FIG. 88;

[0458]FIG. 90 shows a close-up view of the checkout of FIG. 88;

[0459]FIG. 91 shows close-up view of the checkout of FIG. 88 from theoperator's point of view;

[0460]FIG. 92 shows a side view of the conveyor of a second example ofthe checkout of FIG. 88;

[0461]FIG. 93 shows the molecular structure of isophorone nickeldithiolate;

[0462]FIG. 94 shows the absorption spectrum of the dye of FIG. 93;

[0463]FIG. 95 shows the molecular structure camphor sulfonic nickeldithiolate;

[0464]FIG. 96 shows the absorption spectrum of the dye of FIG. 95;

[0465]FIG. 97 is a graph of threshold tag cost as a function ofprojected cost savings;

[0466]FIG. 98 is a schematic diagram of an interface description classused for recording relationships between ranges of item IDs andparticular interface descriptions;

[0467]FIG. 99 is a schematic diagram of an example of interactionbetween a netpage pen and a Web server;

[0468]FIG. 100 is a block diagram of tagging levels in the supply chain;

[0469]FIG. 101 is a schematic view of a first example of a product itemregistration protocol;

[0470]FIG. 102 is a schematic view of a second example of a product itemregistration protocol;

[0471]FIG. 103 is a schematic view of an interface for providing SMSfunctionality;

[0472]FIG. 104 is a schematic view of an example of a packing system;

[0473]FIG. 105 is a schematic perspective view of a first example of ashopping receptacle adapted to sense product items;

[0474]FIG. 106 is a schematic side view of the shopping receptacle ofFIG. 105;

[0475]FIG. 107 of a schematic perspective view of a second example of ashopping receptacle adapted to sense product items;

[0476]FIG. 108 of a schematic side view of a third example of a shoppingreceptacle adapted to sense product items;

[0477]FIG. 109 is a schematic view of a loyalty card incorporating codeddata;

[0478]FIG. 110 is a schematic perspective view of a printing system forprinting coded data on product items;

[0479] FIGS. 111 to 113 are examples of procedures for printing codeddata on product items; and,

[0480]FIG. 114 is schematic representation of an example of a scanningsystem for sensing bar codes and coded data.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

[0481] Note: Memjet™ is a trade mark of Silverbrook Research Pty Ltd,Australia.

[0482] In the preferred embodiment, the invention is configured to workwith the netpage networked computer system, a detailed overview of whichfollows. It will be appreciated that not every implementation willnecessarily embody all or even most of the specific details andextensions discussed below in relation to the basic system. However, thesystem is described in its most complete form to reduce the need forexternal reference when attempting to understand the context in whichthe preferred embodiments and aspects of the present invention operate.

[0483] In brief summary, the preferred form of the netpage systememploys a computer interface in the form of a mapped surface, that is, aphysical surface which contains references to a map of the surfacemaintained in a computer system. The map references can be queried by anappropriate sensing device. Depending upon the specific implementation,the map references may be encoded visibly or invisibly, and defined insuch a way that a local query on the mapped surface yields anunambiguous map reference both within the map and among different maps.The computer system can contain information about features on the mappedsurface, and such information can be retrieved based on map referencessupplied by a sensing device used with the mapped surface. Theinformation thus retrieved can take the form of actions which areinitiated by the computer system on behalf of the operator in responseto the operator's interaction with the surface features.™

[0484] In its preferred form, the netpage system relies on theproduction of, and human interaction with, netpages. These are pages oftext, graphics and images printed on ordinary paper, but which work likeinteractive web pages. Information is encoded on each page using inkwhich is substantially invisible to the unaided human eye. The ink,however, and thereby the coded data, can be sensed by an opticallyimaging pen and transmitted to the netpage system.

[0485] In the preferred form, active buttons and hyperlinks on each pagecan be clicked with the pen to request information from the network orto signal preferences to a network server. In one embodiment, textwritten by hand on a netpage is automatically recognized and convertedto computer text in the netpage system, allowing forms to be filled in.In other embodiments, signatures recorded on a netpage are automaticallyverified, allowing e-commerce transactions to be securely authorized.

[0486] As illustrated in FIG. 1, a printed netpage 1 can represent ainteractive form which can be filled in by the user both physically, onthe printed page, and “electronically”, via communication between thepen and the netpage system. The example shows a “Request” formcontaining name and address fields and a submit button. The netpageconsists of graphic data 2 printed using visible ink, and coded data 3printed as a collection of tags 4 using invisible ink. The correspondingpage description 5, stored on the netpage network, describes theindividual elements of the netpage. In particular it describes the typeand spatial extent (zone) of each interactive element (i.e. text fieldor button in the example), to allow the netpage system to correctlyinterpret input via the netpage. The submit button 6, for example, has azone 7 which corresponds to the spatial extent of the correspondinggraphic 8.

[0487] As illustrated in FIG. 2, the netpage pen 101, a preferred formof which is shown in FIGS. 8 and 9 and described in more detail below,works in conjunction with a personal computer (PC), Web terminal 75, ora netpage printer 601. The netpage printer is an Internet-connectedprinting appliance for home, office or mobile use. The pen is wirelessand communicates securely with the netpage network via a short-rangeradio link 9. Short-range communication is relayed to the netpagenetwork by a local relay function which is either embedded in the PC,Web terminal or netpage printer, or is provided by a separate relaydevice 44. The relay function can also be provided by a mobile phone orother device which incorporates both short-range and longer-rangecommunications functions.

[0488] In an alternative embodiment, the netpage pen utilises a wiredconnection, such as a USB or other serial connection, to the PC, Webterminal, netpage printer or relay device.

[0489] The netpage printer 601, a preferred form of which is shown inFIGS. 11 to 13 and described in more detail below, is able to deliver,periodically or on demand, personalized newspapers, magazines, catalogs,brochures and other publications, all printed at high quality asinteractive netpages. Unlike a personal computer, the netpage printer isan appliance which can be, for example, wall-mounted adjacent to an areawhere the morning news is first consumed, such as in a user's kitchen,near a breakfast table, or near the household's point of departure forthe day. It also comes in tabletop, desktop, portable and miniatureversions. netpages printed at their point of consumption combine theease-of-use of paper with the timeliness and interactivity of aninteractive medium.

[0490] As shown in FIG. 2, the netpage pen 101 interacts with the codeddata on a printed netpage 1 (or product item 201) and communicates theinteraction via a short-range radio link 9 to a relay. The relay sendsthe interaction to the relevant netpage page server 10 forinterpretation. In appropriate circumstances, the page server sends acorresponding message to application computer software running on anetpage application server 13. The application server may in turn send aresponse which is printed on the originating printer.

[0491] In an alternative embodiment, the PC, Web terminal, netpageprinter or relay device may communicate directly with local or remoteapplication software, including a local or remote Web server. Relatedly,output is not limited to being printed by the netpage printer. It canalso be displayed on the PC or Web terminal, and further interaction canbe screen-based rather than paper-based, or a mixture of the two.

[0492] The netpage system is made considerably more convenient in thepreferred embodiment by being used in conjunction with high-speedmicroelectromechanical system (MEMS) based inkjet (Memjet™) printers. Inthe preferred form of this technology, relatively high-speed andhigh-quality printing is made more affordable to consumers. In itspreferred form, a netpage publication has the physical characteristicsof a traditional newsmagazine, such as a set of letter-size glossy pagesprinted in full color on both sides, bound together for easy navigationand comfortable handling.

[0493] The netpage printer exploits the growing availability ofbroadband Internet access. Cable service is available to 95% ofhouseholds in the United States, and cable modem service offeringbroadband Internet access is already available to 20% of these. Thenetpage printer can also operate with slower connections, but withlonger delivery times and lower image quality. Indeed, the netpagesystem can be enabled using existing consumer inkjet and laser printers,although the system will operate more slowly and will therefore be lessacceptable from a consumer's point of view. In other embodiments, thenetpage system is hosted on a private intranet. In still otherembodiments, the netpage system is hosted on a single computer orcomputer-enabled device, such as a printer.

[0494] netpage publication servers 14 on the netpage network areconfigured to deliver print-quality publications to netpage printers.Periodical publications are delivered automatically to subscribingnetpage printers via pointcasting and multicasting Internet protocols.Personalized publications are filtered and formatted according toindividual user profiles.

[0495] A netpage printer can be configured to support any number ofpens, and a pen can work with any number of netpage printers. In thepreferred implementation, each netpage pen has a unique identifier. Ahousehold may have a collection of colored netpage pens, one assigned toeach member of the family. This allows each user to maintain a distinctprofile with respect to a netpage publication server or applicationserver.

[0496] A netpage pen can also be registered with a netpage registrationserver 11 and linked to one or more payment card accounts. This allowse-commerce payments to be securely authorized using the netpage pen. Thenetpage registration server compares the signature captured by thenetpage pen with a previously registered signature, allowing it toauthenticate the user's identity to an e-commerce server. Otherbiometrics can also be used to verify identity. A version of the netpagepen includes fingerprint scanning, verified in a similar way by thenetpage registration server.

[0497] Although a netpage printer may deliver periodicals such as themorning newspaper without user intervention, it can be configured neverto deliver unsolicited junk mail. In its preferred form, it onlydelivers periodicals from subscribed or otherwise authorized sources. Inthis respect, the netpage printer is unlike a fax machine or e-mailaccount which is visible to any junk mailer who knows the telephonenumber or email address.

[0498] 1 Netpage System Architecture

[0499] Each object model in the system is described using a UnifiedModeling Language (UML) class diagram. A class diagram consists of a setof object classes connected by relationships, and two kinds ofrelationships are of interest here: associations and generalizations. Anassociation represents some kind of relationship between objects, i.e.between instances of classes. A generalization relates actual classes,and can be understood in the following way: if a class is thought of asthe set of all objects of that class, and class A is a generalization ofclass B, then B is simply a subset of A. The UML does not directlysupport second-order modelling—i.e. classes of classes.

[0500] Each class is drawn as a rectangle labelled with the name of theclass. It contains a list of the attributes of the class, separated fromthe name by a horizontal line, and a list of the operations of theclass, separated from the attribute list by a horizontal line. In theclass diagrams which follow, however, operations are never modelled.

[0501] An association is drawn as a line joining two classes, optionallylabelled at either end with the multiplicity of the association. Thedefault multiplicity is one. An asterisk (*) indicates a multiplicity of“many”, i.e. zero or more. Each association is optionally labelled withits name, and is also optionally labelled at either end with the role ofthe corresponding class. An open diamond indicates an aggregationassociation (“is-part-of”), and is drawn at the aggregator end of theassociation line.

[0502] A generalization relationship (“is-a”) is drawn as a solid linejoining two classes, with an arrow (in the form of an open triangle) atthe generalization end.

[0503] When a class diagram is broken up into multiple diagrams, anyclass which is duplicated is shown with a dashed outline in all but themain diagram which defines it. It is shown with attributes only where itis defined.

[0504] 1.1 Netpages

[0505] netpages are the foundation on which a netpage network is built.They provide a paper-based user interface to published information andinteractive services.

[0506] A netpage consists of a printed page (or other surface region)invisibly tagged with references to an online description of the page.The online page description is maintained persistently by a netpage pageserver. The page description describes the visible layout and content ofthe page, including text, graphics and images. It also describes theinput elements on the page, including buttons, hyperlinks, and inputfields. A netpage allows markings made with a netpage pen on its surfaceto be simultaneously captured and processed by the netpage system.

[0507] Multiple netpages can share the same page description. However,to allow input through otherwise identical pages to be distinguished,each netpage is assigned a unique page identifier. This page ID hassufficient precision to distinguish between a very large number ofnetpages.

[0508] Each reference to the page description is encoded in a printedtag. The tag identifies the unique page on which it appears, and therebyindirectly identifies the page description. The tag also identifies itsown position on the page. Characteristics of the tags are described inmore detail below.

[0509] Tags are printed in infrared-absorptive ink on any substratewhich is infrared-reflective, such as ordinary paper. Near-infraredwavelengths are invisible to the human eye but are easily sensed by asolid-state image sensor with an appropriate filter.

[0510] A tag is sensed by an area image sensor in the netpage pen, andthe tag data is transmitted to the netpage system via the nearestnetpage printer. The pen is wireless and communicates with the netpageprinter via a short-range radio link. Tags are sufficiently small anddensely arranged that the pen can reliably image at least one tag evenon a single click on the page. It is important that the pen recognizethe page ID and position on every interaction with the page, since theinteraction is stateless. Tags are error-correctably encoded to makethem partially tolerant to surface damage.

[0511] The netpage page server maintains a unique page instance for eachprinted netpage, allowing it to maintain a distinct set of user-suppliedvalues for input fields in the page description for each printednetpage.

[0512] The relationship between the page description, the page instance,and the printed netpage is shown in FIG. 4. The printed netpage may bepart of a printed netpage document 45. The page instance is associatedwith both the netpage printer which printed it and, if known, thenetpage user who requested it.

[0513] As shown in FIG. 4, one or more netpages may also be associatedwith a physical object such as a product item, for example when printedonto the product item's label, packaging, or actual surface.

[0514] 1.2 Coded Data on Surfaces Using Netpage Tags

[0515] Various netpage coding schemes and patterns are described in thepresent applicants' co-pending U.S. application U.S. Ser. No. 09/575,154entitled “Identity-Coded Surface with Reference Points”, filed 23 May2000; co-pending U.S. application U.S. Ser. No. 10/120,441 entitled“Cyclic Position Codes”, filed 12 Apr. 2002; co-pending U.S. applicationU.S. Ser. No. 10/309,358 entitled “Rotationally Symmetric Tags”, filed 4Dec. 2002; co-pending U.S. application U.S. Ser. No. 10/409,864 entitled“Orientation—Indicating Cyclic Position Codes”, filed 9 Apr. 2003; andco-pending U.S. application U.S. Ser. No. ______ entitled “SymmetricTags”, filed 4 Mar. 2004 (Docket number NPT037).

[0516] 1.2.1 Tag Data Content

[0517] In a preferred form, each tag identifies the region in which itappears, and the location of that tag within the region. A tag may alsocontain flags which relate to the region as a whole or to the tag. Oneor more flag bits may, for example, signal a tag sensing device toprovide feedback indicative of a function associated with the immediatearea of the tag, without the sensing device having to refer to adescription of the region. A netpage pen may, for example, illuminate an“active area” LED when in the zone of a hyperlink.

[0518] The tags preferably tile the entire page, and are sufficientlysmall and densely arranged that the pen can reliably image at least onetag even on a single click on the page. It is important that the penrecognize the page ID and position on every interaction with the page,since the interaction is stateless.

[0519] In a preferred embodiment, the region to which a tag referscoincides with an entire page, and the region ID encoded in the tag istherefore synonymous with the page ID of the page on which the tagappears. In other embodiments, the region to which a tag refers can bean arbitrary subregion of a page or other surface. For example, it cancoincide with the zone of an interactive element, in which case theregion ID can directly identify the interactive element.

[0520] Each tag typically contains 16 bits of tag ID, at least 90 bitsof region ID, and a number of flag bits. Assuming a maximum tag densityof 64 per square inch, a 16-bit tag ID supports a region size of up to1024 square inches. Larger regions can be mapped continuously withoutincreasing the tag ID precision simply by using abutting regions andmaps. The distinction between a region ID and a tag ID is mostly one ofconvenience. For most purposes the concatenation of the two can beconsidered as a globally unique tag ID. Conversely, it may also beconvenient to introduce structure into the tag ID, for example to definethe x and y coordinates of the tag. A 90-bit region ID allows 2⁹⁰ (10²⁷˜or a thousand trillion trillion) different regions to be uniquelyidentified. A 100-bit region ID allows 2¹⁰⁰ (˜10³⁰ or a million trilliontrillion) different regions to be uniquely identified. Tags may alsocontain type information, and a region may be tagged with a mixture oftag types. For example, a region may be tagged with one set of tagsencoding x coordinates and another set, interleaved with the first,encoding y coordinates. It will be appreciated the region ID and tag IDprecision may be more or less than just described depending on theenvironment in which the system will be used.

[0521] 1.2.2 Tag Data Encoding

[0522] In one embodiment, the 120 bits of tag data are redundantlyencoded using a (15, 5) Reed-Solomon code. This yields 360 encoded bitsconsisting of 6 codewords of 15 4-bit symbols each. The (15, 5) codeallows up to 5 symbol errors to be corrected per codeword, i.e. it istolerant of a symbol error rate of up to 33% per codeword.

[0523] Each 4-bit symbol is represented in a spatially coherent way inthe tag, and the symbols of the six codewords are interleaved spatiallywithin the tag. This ensures that a burst error (an error affectingmultiple spatially adjacent bits) damages a minimum number of symbolsoverall and a minimum number of symbols in any one codeword, thusmaximising the likelihood that the burst error can be fully corrected.

[0524] Any suitable error-correcting code can be used in place of a (15,5) Reed-Solomon code, for example: a Reed-Solomon code with more or lessredundancy, with the same or different symbol and codeword sizes;another block code; or a different kind of code, such as a convolutionalcode (see, for example, Stephen B. Wicker, Error Control Systems forDigital Communication and Storage, Prentice-Hall 1995, the contents ofwhich a herein incorporated by reference thereto).

[0525] In order to support “single-click” interaction with a taggedregion via a sensing device, the sensing device must be able to see atleast one entire tag in its field of view no matter where in the regionor at what orientation it is positioned. The required diameter of thefield of view of the sensing device is therefore a function of the sizeand spacing of the tags.

[0526] 1.2.3 Tag Structure

[0527]FIG. 5a shows a tag 4, in the form of tag 726 with fourperspective targets 17. The tag 726 represents sixty 4-bit Reed-Solomonsymbols 747 (see description of FIGS. 44 to 46 below for discussion ofsymbols), for a total of 240 bits. The tag represents each “one” bit bythe presence of a mark 748, referred to as a macrodot, and each “zero”bit by the absence of the corresponding macrodot. FIG. 5c shows a squaretiling 728 of nine tags, containing all “one” bits for illustrativepurposes. It will be noted that the perspective targets are designed tobe shared between adjacent tags. FIG. 6 shows a square tiling of 16 tagsand a corresponding minimum field of view 193, which spans the diagonalsof two tags.

[0528] Using a (15, 7) Reed-Solomon code, 112 bits of tag data areredundantly encoded to produce 240 encoded bits. The four codewords areinterleaved spatially within the tag to maximize resilience to bursterrors. Assuming a 16-bit tag ID as before, this allows a region ID ofup to 92 bits.

[0529] The data-bearing macrodots 748 of the tag are designed to notoverlap their neighbors, so that groups of tags cannot producestructures that resemble targets. This also saves ink. The perspectivetargets allow detection of the tag, so further targets are not required.

[0530] Although the tag may contain an orientation feature to allowdisambiguation of the four possible orientations of the tag relative tothe sensor, the present invention is concerned with embeddingorientation data in the tag data. For example, the four codewords can bearranged so that each tag orientation (in a rotational sense) containsone codeword placed at that orientation, as shown in FIG. 5a, where eachsymbol is labelled with the number of its codeword (1-4) and theposition of the symbol within the codeword (A-O). Tag decoding thenconsists of decoding one codeword at each rotational orientation. Eachcodeword can either contain a single bit indicating whether it is thefirst codeword, or two bits indicating which codeword it is. The latterapproach has the advantage that if, say, the data content of only onecodeword is required, then at most two codewords need to be decoded toobtain the desired data. This may be the case if the region ID is notexpected to change within a stroke and is thus only decoded at the startof a stroke. Within a stroke only the codeword containing the tag ID isthen desired. Furthermore, since the rotation of the sensing devicechanges slowly and predictably within a stroke, only one codewordtypically needs to be decoded per frame.

[0531] It is possible to dispense with perspective targets altogetherand instead rely on the data representation being self-registering. Inthis case each bit value (or multi-bit value) is typically representedby an explicit glyph, i.e. no bit value is represented by the absence ofa glyph. This ensures that the data grid is well-populated, and thusallows the grid to be reliably identified and its perspective distortiondetected and subsequently corrected during data sampling. To allow tagboundaries to be detected, each tag data must contain a marker pattern,and these must be redundantly encoded to allow reliable detection. Theoverhead of such marker patterns is similar to the overhead of explicitperspective targets. Various such schemes are described in the presentapplicants' co-pending PCT application PCT/AU01/01274 filed 11 Oct.2001.

[0532] The arrangement 728 of FIG. 5c shows that the square tag 726 canbe used to fully tile or tesselate, i.e. without gaps or overlap, aplane of arbitrary size.

[0533] Although in preferred embodiments the tagging schemes describedherein encode a single data bit using the presence or absence of asingle undifferentiated macrodot, they can also use sets ofdifferentiated glyphs to represent single-bit or multi-bit values, suchas the sets of glyphs illustrated in the present applicants' co-pendingPCT application PCT/AU01/01274 filed 11 Oct. 2001.

[0534] 1.2.4.1 Macrodot Packing Schemes

[0535]FIG. 44 shows a triangular macrodot packing 700 with a four-bitsymbol unit 702 outlined. The area of the symbol unit is given by

A _(UNIT)=2{square root}{square root over (3)} s²≡3.5 s²

[0536] where s the spacing of adjacent macrodots. FIG. 45 shows a squaremacrodot packing 704 with a four-bit symbol unit 706 outlined. The areaof the symbol unit is given by

A_(UNIT)=4 s²

[0537]FIG. 46 shows a hexagonal macrodot packing 708 with a four-bitsymbol unit 710 outlined. The area of the symbol unit is given by

A _(UNIT)=3{square root}{square root over (3)} s²≡5.2 s²

[0538] Of these packing schemes, the triangular packing scheme gives thegreatest macrodot density for a particular macrodot spacing s.

[0539] In preferred embodiments, s has a value between 100 μm and 200μm.

[0540] 1.2.4.2 Tag Designs

[0541]FIG. 46 shows a one-sixth segment 712 of a hexagonal tag, with thesegment containing a maximum of 11 four-bit symbols with the triangularmacrodot packing shown in FIG. 44. The target 17 is shared with adjacentsegments. Each tag segment can, by way of example, support a codeword ofan (11,k) Reed-Solomon code, i.e. a punctured (15,k) code, with theability to detect u=11-k symbol errors, or correct t=[(11-k)/2] symbolerrors. For example, if k=7 then u=4 and t=2.

[0542]FIG. 47 shows a one-quarter segment 718 of a square tag, with thesegment containing a maximum of 15 four-bit symbols with the squaremacrodot packing shown in FIG. 45. Each tag segment can, by way ofexample, support a codeword of a (15,k) Reed-Solomon code, with theability to detect u=15-k symbol errors, or correct t=[(15-k)/2] symbolerrors. For example, if k=7 then u=8 and t=4.

[0543] 1.2.4.3 Hexagonal Tag Design

[0544]FIG. 48 shows a logical layout of a hexagonal tag 722 using thetag segment 712 of FIG. 46, with six interleaved 2⁴-ary (11,k)codewords. FIG. 49 shows the macrodot layout of the hexagonal tag 722 ofFIG. 51. FIG. 53 shows an arrangement 724 of seven abutting tags 722 ofthe design of FIG. 48, with shared targets 17. The arrangement 724 showsthat the hexagonal tag 722 can be used to tesselate a plane of arbitrarysize.

[0545] 1.2.4.4 Alternative Hexagonal Tag Design 1

[0546]FIG. 51 shows the logical layout of an alternative hexagonal tag.This tag design is described in detail in the present applicants'co-pending U.S. application U.S. Ser. No. 10/409,864 entitled“Orientation-Indicating Cyclic Position Codes”.

[0547] The tag contains a 2⁴-ary (6,1)cyclic position codeword(0,5,6,9,A₁₆,F₁₆) which can 20 be decoded at any of the six possibleorientations of the tag to determine the actual orientation of the tag.Symbols which are part of the cyclic position codeword have a prefix of“R” and are numbered 0 to 5 in order of increasing significance, and areshown shaded in FIG. 52.

[0548] The tag locally contains three complete codewords which are usedto encode information unique to the tag. Each codeword is of a punctured2⁴-ary (9,5) Reed-Solomon code. The tag therefore encodes up to 60 bitsof information unique to the tag. The tag also contains fragments ofthree codewords which are distributed across three adjacent tags andwhich are used to encode information common to a set of contiguous tags.Each codeword is of a punctured 2⁴-ary (9,5) Reed-Solomon code. Anythree adjacent tags therefore together encode up to 60 bits ofinformation common to a set of contiguous tags.

[0549] The layout of the three complete codewords, distributed acrossthree adjacent tags, is shown in FIG. 53. In relation to thesedistributed codewords there are three types of tag. These are referredto as P, Q and R in order of increasing significance.

[0550] The P, Q and R tags are repeated in a continuous tiling of tagswhich guarantees the any set of three adjacent tags contains one tag ofeach type, and therefore contains a complete set of distributedcodewords. The tag type, used to determine the registration of thedistributed codewords with respect to a particular set of adjacent tags,is encoded in one of the local codewords of each tag.

[0551] 1.2.4.4 Alternative Hexagonal Tag Design 2

[0552]FIG. 54 shows the logical layout of another alternative hexagonaltag. This tag design is described in detail in the present applicants'co-pending U.S. application U.S. Ser. No. ______ entitled “SymmetricTags” (docket number NPT037US).

[0553]FIG. 54 shows a logical layout of a hexagonal tag 750 using thetag segment of FIG. 46, with one local 2⁴-ary (12,k) codewordinterleaved with eighteen 3-symbol fragments of eighteen distributed2⁴-ary (9,k) codewords.

[0554] In the layout of FIG. 54, the twelve 4-bit symbols of the localcodeword are labelled G1 through G12, and are shown with a dashedoutline. Each symbol of the eighteen fragments of the eighteendistributed codewords is labelled with an initial prefix of A through F,indicating which of six nominal codewords the symbol belongs to, asubsequent prefix of S through U, indicating which 3-symbol part of thecodeword the symbol belongs to, and a suffix of 1 through 3, indicatingwhich of the three possible symbols the symbol is.

[0555] Tag 750 is structured so that the minimal field of view allowsthe recovery of the local codeword G of at least one tag, and the entireset of distributed codewords AP through FR via fragments of tags of typeP, Q and R included in the field of view. Furthermore, the continuoustiling of tag 750 ensures that there is a codeword available with aknown layout for each possible rotational and translational combination(of which there are eighteen). Each distributed codeword includes datawhich identifies the rotation of the codeword in relation to the tiling,thus allowing the rotation of the tiling with respect to the field ofview to be determined from decoded data rather than from otherstructures, and the local codeword to be decoded at the correctorientation.

[0556]FIG. 55 shows the logical layout of the hexagonal tag 750 of FIG.54, re-arranged to show the distributed 3-symbol fragments whichcontribute to the same codewords. For example, if the central tag shownin FIG. 54 were a P-type tag, then the six distributed codewords shownin the figure would be the AP, BP, CP, DP, EP and FP codewords. FIG. 55also shows the local G codeword of the tag. Clearly, given thedistributed and repeating nature of the distributed codewords, differentfragments from the ones shown in the figure can be used to build thecorresponding codewords.

[0557] 1.2.4 Tag Image Processing and Decoding

[0558]FIG. 7 shows a tag image processing and decoding process flow. Araw image 202 of the tag pattern is acquired (at 200), for example viaan image sensor such as a CCD image sensor, CMOS image sensor, or ascanning laser and photodiode image sensor. The raw image is thentypically enhanced (at 204) to produce an enhanced image 206 withimproved contrast and more uniform pixel intensities. Image enhancementmay include global or local range expansion, equalisation, and the like.The enhanced image 206 is then typically filtered (at 208) to produce afiltered image 210. Image filtering may consist of low-pass filtering,with the low-pass filter kernel size tuned to obscure macrodots but topreserve targets. The filtering step 208 may include additionalfiltering (such as edge detection) to enhance target features. Thefiltered image 210 is then processed to locate target features (at 212),yielding a set of target points. This may consist of a search for targetfeatures whose spatial inter-relationship is consistent with the knowngeometry of a tag. Candidate targets may be identified directly frommaxima in the filtered image 210, or may the subject of furthercharacterisation and matching, such as via their (binary or grayscale)shape moments (typically computed from pixels in the enhanced image 206based on local maxima in the filtered image 210), as described in U.S.patent application Ser. No. 09/575,154. The search typically starts fromthe center of the field of view. The target points 214 found by thesearch step 212 indirectly identify the location of the tag in thethree-dimensional space occupied by the image sensor and its associatedoptics. Since the target points 214 are derived from the (binary orgrayscale) centroids of the targets, they are typically defined tosub-pixel precision.

[0559] It may be useful to determine the actual 3D transform of the tag(at 216), and, by extension, the 3D transform (or pose) 218 of thesensing device relative to the tag. This may be done analytically, asdescribed in U.S. patent application Ser. No. 09/575,154, or using amaximum likelihood estimator (such as least squares adjustment) to fitparameter values to the 3D transform given the observedperspective-distorted target points (as described in P. R. Wolf and B.A. Dewitt, Elements of Photogrammetry with Applications in GIS, 3rdEdition, McGraw Hill, February 2000, the contents of which are hereinincorporated by reference thereto). The 3D transform includes the 3Dtranslation of the tag, the 3D orientation (rotation) of the tag, andthe focal length and viewport scale of the sensing device, thus givingeight parameters to be fitted, or six parameters if the focal length andviewport scale are known (e.g. by design or from a calibration step).Each target point yields a pair of observation equations, relating anobserved coordinate to a known coordinate. If eight parameters are beingfitted, then five or more target points are needed to provide sufficientredundancy to allow maximum likelihood estimation. If six parameters arebeing fitted, then four or more target points are needed. If the tagdesign contains more targets than are minimally required to allowmaximum likelihood estimation, then the tag can be recognised anddecoded even if up to that many of its targets are damaged beyondrecognition.

[0560] To allow macrodot values to be sampled accurately, theperspective transform of the tag must be inferred. Four of the targetpoints are taken to be the perspective-distorted comers of a rectangleof known size in tag space, and the eight-degree-of-freedom perspectivetransform 222 is inferred (at 220), based on solving the well-understoodequations relating the four tag-space and image-space point pairs (seeHeckbert, P., Fundamentals of Texture Mapping and Image Warping, MastersThesis, Dept. of EECS, U. of California at Berkeley, Technical ReportNo. UCB/CSD 89/516, June 1989, the contents of which are hereinincorporated by reference thereto). The perspective transform mayalternatively be derived from the 3D transform 218, if available.

[0561] The inferred tag-space to image-space perspective transform 222is used to project (at 224) each known data bit position in tag spaceinto image space where the real-valued position is used to bi-linearly(or higher-order) interpolate (at 224) the four (or more) relevantadjacent pixels in the enhanced input image 206. The resultant macrodotvalue is compared with a suitable threshold to determine whether itrepresents a zero bit or a one bit.

[0562] One the bits of one or more complete codeword have been sampled,the codewords are decoded (at 228) to obtain the desired data 230encoded in the tag. Redundancy in the codeword may be used to detecterrors in the sampled data, or to correct errors in the sampled data.

[0563] As discussed in U.S. patent application Ser. No. 09/575,154, theobtained tag data 230 may directly or indirectly identify the surfaceregion containing the tag and the position of the tag within the region.An accurate position of the sensing device relative to the surfaceregion can therefore be derived from the tag data 230 and the 3Dtransform 218 of the sensing device relative to the tag.

[0564] 1.2.6 Tag Map

[0565] Decoding a tag results in a region ID, a tag ID, and atag-relative pen transform. Before the tag ID and the tag-relative penlocation can be translated into an absolute location within the taggedregion, the location of the tag within the region must be known. This isgiven by a tag map, a function which maps each tag ID in a tagged regionto a corresponding location. The tag map class diagram is shown in FIG.22, as part of the netpage printer class diagram.

[0566] A tag map reflects the scheme used to tile the surface regionwith tags, and this can vary according to surface type. When multipletagged regions share the same tiling scheme and the same tag numberingscheme, they can also share the same tag map.

[0567] The tag map for a region must be retrievable via the region ID.Thus, given a region ID, a tag ID and a pen transform, the tag map canbe retrieved, the tag ID can be translated into an absolute tag locationwithin the region, and the tag-relative pen location can be added to thetag location to yield an absolute pen location within the region.

[0568] The tag ID may have a structure which assists translation throughthe tag map. It may, for example, encode cartesian coordinates or polarcoordinates, depending on the surface type on which it appears. The tagID structure is dictated by and known to the tag map, and tag IDsassociated with different tag maps may therefore have differentstructures. For example, the tag ID may simply encode a pair of x and ycoordinates of the tag, in which case the tag map may simply consist ofrecord of the coordinate precision. If the coordinate precision isfixed, then the tag map can be implicit.

[0569] 1.2.7 Tagging Schemes

[0570] Two distinct surface coding schemes are of interest, both ofwhich use the tag structure described earlier in this section. Thepreferred coding scheme uses “location-indicating” tags as alreadydiscussed. An alternative coding scheme uses object-indicating tags.

[0571] A location-indicating tag contains a tag ID which, whentranslated through the tag map associated with the tagged region, yieldsa unique tag location within the region. The tag-relative location ofthe pen is added to this tag location to yield the location of the penwithin the region. This in turn is used to determine the location of thepen relative to a user interface element in the page descriptionassociated with the region. Not only is the user interface elementitself identified, but a location relative to the user interface elementis identified. Location-indicating tags therefore trivially support thecapture of an absolute pen path in the zone of a particular userinterface element.

[0572] An object-indicating tag contains a tag ID which directlyidentifies a user interface element in the page description associatedwith the region. All the tags in the zone of the user interface elementidentify the user interface element, making them all identical andtherefore indistinguishable. Object-indicating tags do not, therefore,support the capture of an absolute pen path. They do, however, supportthe capture of a relative pen path. So long as the position samplingfrequency exceeds twice the encountered tag frequency, the displacementfrom one sampled pen position to the next within a stroke can beunambiguously determined.

[0573] With either tagging scheme, the tags function in cooperation withassociated visual elements on the netpage as user interactive elementsin that a user can interact with the printed page using an appropriatesensing device in order for tag data to be read by the sensing deviceand for an appropriate response to be generated in the netpage system.

[0574] In many circumstances, where it is not required to determine theabsolute pen path, either object-indicating tags or position-indicatingtags can be used. For the purposes of simplicity, the remainder of thedescription will focus on the use of position-indicating tags, but itwill be appreciated that this should be taken to include the use ofobject-indicating tags within its scope. In this instance, a referenceto digital ink should be taken to include object-indicating “digitalink”, even though digital ink is nominally position-indicating.

[0575] 1.3 Document and Page Descriptions

[0576] A preferred embodiment of a document and page description classdiagram is shown in FIGS. 25 and 26.

[0577] In the netpage system a document is described at three levels. Atthe most abstract level the document 836 has a hierarchical structurewhose terminal elements 839 are associated with content objects 840 suchas text objects, text style objects, image objects, etc. Once thedocument is printed on a printer with a particular page size andaccording to a particular user's scale factor preference, the documentis paginated and otherwise formatted. Formatted terminal elements 835will in some cases be associated with content objects which aredifferent from those associated with their corresponding terminalelements, particularly where the content objects are style-related. Eachprinted instance of a document and page is also described separately, toallow input captured through a particular page instance 830 to berecorded separately from input captured through other instances of thesame page description.

[0578] The presence of the most abstract document description on thepage server allows a user to request a copy of a document without beingforced to accept the source document's specific format. The user may berequesting a copy through a printer with a different page size, forexample. Conversely, the presence of the formatted document descriptionon the page server allows the page server to efficiently interpret useractions on a particular printed page.

[0579] A formatted document 834 consists of a set of formatted pagedescriptions 5, each of which consists of a set of formatted terminalelements 835. Each formatted element has a spatial extent or zone 58 onthe page. This defines the active area of input elements such ashyperlinks and input fields.

[0580] A document instance 831 corresponds to a formatted document 834.It consists of a set of page instances 830, each of which corresponds toa page description 5 of the formatted document. Each page instance 830describes a single unique printed netpage 1, and records the page ID 50of the netpage. A page instance is not part of a document instance if itrepresents a copy of a page requested in isolation.

[0581] A page instance consists of a set of terminal element instances832. An element instance only exists if it records instance-specificinformation. Thus, a hyperlink instance exists for a hyperlink elementbecause it records a transaction ID 55 which is specific to the pageinstance, and a field instance exists for a field element because itrecords input specific to the page instance. An element instance doesnot exist, however, for static elements such as textflows.

[0582] A terminal element can be a static element 843, a hyperlinkelement 844, a field element 845 or a page server command element 846,as shown in FIG. 27. A static element 843 can be a style element 847with an associated style object 854, a textflow element 848 with anassociated styled text object 855, an image element 849 with anassociated image element 856, a graphic element 850 with an associatedgraphic object 857, a video clip element 851 with an associated videoclip object 858, an audio clip element 852 with an associated audio clipobject 859, or a script element 853 with an associated script object860, as shown in FIG. 28.

[0583] A page instance has a background field 833 which is used torecord any digital ink captured on the page which does not apply to aspecific input element.

[0584] In the preferred form of the invention, a tag map 811 isassociated with each page instance to allow tags on the page to betranslated into locations on the page.

[0585] 1.4 The Netpage Network

[0586] In a preferred embodiment, a netpage network consists of adistributed set of netpage page servers 10, netpage registration servers11, netpage ID servers 12, netpage application servers 13, netpagepublication servers 14, Web terminals 75, netpage printers 601, andrelay devices 44 connected via a network 19 such as the Internet, asshown in FIG. 3.

[0587] The netpage registration server 11 is a server which recordsrelationships between users, pens, printers, applications andpublications, and thereby authorizes various network activities. Itauthenticates users and acts as a signing proxy on behalf ofauthenticated users in application transactions. It also provideshandwriting recognition services. As described above, a netpage pageserver 10 maintains persistent information about page descriptions andpage instances. The netpage network includes any number of page servers,each handling a subset of page instances. Since a page server alsomaintains user input values for each page instance, clients such asnetpage printers send netpage input directly to the appropriate pageserver. The page server interprets any such input relative to thedescription of the corresponding page.

[0588] A netpage ID server 12 allocates document IDs 51 on demand, andprovides load-balancing of page servers via its ID allocation scheme.

[0589] A netpage printer uses the Internet Distributed Name System(DNS), or similar, to resolve a netpage page ID 50 into the networkaddress of the netpage page server handling the corresponding pageinstance.

[0590] A netpage application server 13 is a server which hostsinteractive netpage applications. A netpage publication server 14 is anapplication server which publishes netpage documents to netpageprinters. They are described in detail in Section 2.

[0591] netpage servers can be hosted on a variety of network serverplatforms from manufacturers such as IBM, Hewlett-Packard, and Sun.Multiple netpage servers can run concurrently on a single host, and asingle server can be distributed over a number of hosts. Some or all ofthe functionality provided by netpage servers, and in particular thefunctionality provided by the ID server and the page server, can also beprovided directly in a netpage appliance such as a netpage printer, in acomputer workstation, or on a local network.

[0592] 1.5 The Netpage Printer

[0593] The netpage printer 601 is an appliance which is registered withthe netpage system and prints netpage documents on demand and viasubscription. Each printer has a unique printer ID 62, and is connectedto the netpage network via a network such as the Internet, ideally via abroadband connection.

[0594] Apart from identity and security settings in non-volatile memory,the netpage printer contains no persistent storage. As far as a user isconcerned, “the network is the computer”. netpages functioninteractively across space and time with the help of the distributednetpage page servers 10, independently of particular netpage printers.

[0595] The netpage printer receives subscribed netpage documents fromnetpage publication servers 14. Each document is distributed in twoparts: the page layouts, and the actual text and image objects whichpopulate the pages. Because of personalization, page layouts aretypically specific to a particular subscriber and so are pointcast tothe subscriber's printer via the appropriate page server. Text and imageobjects, on the other hand, are typically shared with other subscribers,and so are multicast to all subscribers' printers and the appropriatepage servers.

[0596] The netpage publication server optimizes the segmentation ofdocument content into pointcasts and multicasts. After receiving thepointcast of a document's page layouts, the printer knows whichmulticasts, if any, to listen to.

[0597] Once the printer has received the complete page layouts andobjects that define the document to be printed, it can print thedocument.

[0598] The printer rasterizes and prints odd and even pagessimultaneously on both sides of the sheet. It contains duplexed printengine controllers 760 and print engines utilizing Memjet™ printheads350 for this purpose.

[0599] The printing process consists of two decoupled stages:rasterization of page descriptions, and expansion and printing of pageimages. The raster image processor (RIP) consists of one or morestandard DSPs 757 running in parallel. The duplexed print enginecontrollers consist of custom processors which expand, dither and printpage images in real time, synchronized with the operation of theprintheads in the print engines.

[0600] Printers not enabled for IR printing have the option to printtags using IR-absorptive black ink, although this restricts tags tootherwise empty areas of the page. Although such pages have more limitedfunctionality than IR-printed pages, they are still classed as netpages.

[0601] A normal netpage printer prints netpages on sheets of paper. Morespecialised netpage printers may print onto more specialised surfaces,such as globes. Each printer supports at least one surface type, andsupports at least one tag tiling scheme, and hence tag map, for eachsurface type. The tag map 811 which describes the tag tiling schemeactually used to print a document becomes associated with that documentso that the document's tags can be correctly interpreted.

[0602]FIG. 2 shows the netpage printer class diagram, reflectingprinter-related information maintained by a registration server 11 onthe netpage network.

[0603] A preferred embodiment of the netpage printer is described ingreater detail in Section 6 below, with reference to FIGS. 11 to 16.

[0604] 1.5.1 Memjet™ Printheads

[0605] The netpage system can operate using printers made with a widerange of digital printing technologies, including thermal inkjet,piezoelectric inkjet, laser electrophotographic, and others.

[0606] However, for wide consumer acceptance, it is desirable that anetpage printer have the following characteristics:

[0607] photographic quality color printing

[0608] high quality text printing

[0609] high reliability

[0610] low printer cost

[0611] low ink cost

[0612] low paper cost

[0613] simple operation

[0614] nearly silent printing

[0615] high printing speed

[0616] simultaneous double sided printing

[0617] compact form factor

[0618] low power consumption

[0619] No commercially available printing technology has all of thesecharacteristics.

[0620] To enable to production of printers with these characteristics,the present applicant has invented a new print technology, referred toas Memjet™ technology. Memjet™ is a drop-on-demand inkjet technologythat incorporates pagewidth printheads fabricated usingmicroelectromechanical systems (MEMS) technology. FIG. 17 shows a singleprinting element 300 of a Memjet™ printhead. The netpage wallprinterincorporates 168960 printing elements 300 to form a 1600 dpi pagewidthduplex printer. This printer simultaneously prints cyan, magenta,yellow, black, and infrared inks as well as paper conditioner and inkfixative.

[0621] The printing element 300 is approximately 110 microns long by 32microns wide. Arrays of these printing elements are formed on a siliconsubstrate 301 that incorporates CMOS logic, data transfer, timing, anddrive circuits (not shown).

[0622] Major elements of the printing element 300 are the nozzle 302,the nozzle rim 303, the nozzle chamber 304, the fluidic seal 305, theink channel rim 306, the lever arm 307, the active actuator beam pair308, the passive actuator beam pair 309, the active actuator anchor 310,the passive actuator anchor 311, and the ink inlet 312.

[0623] The active actuator beam pair 308 is mechanically joined to thepassive actuator beam pair 309 at the join 319. Both beams pairs areanchored at their respective anchor points 310 and 311. The combinationof elements 308, 309, 310, 311, and 319 form a cantileveredelectrothermal bend actuator 320.

[0624] While printing, the printhead CMOS circuitry distributes datafrom the print engine controller to the correct printing element,latches the data, and buffers the data to drive the electrodes 318 ofthe active actuator beam pair 308. This causes an electrical current topass through the beam pair 308 for about one microsecond, resulting inJoule heating. The temperature increase resulting from Joule heatingcauses the beam pair 308 to expand. As the passive actuator beam pair309 is not heated, it does not expand, resulting in a stress differencebetween the two beam pairs. This stress difference is partially resolvedby the cantilevered end of the electrothermal bend actuator 320 bendingtowards the substrate 301. The lever arm 307 transmits this movement tothe nozzle chamber 304. The nozzle chamber 304 moves about two micronsto the position shown in FIG. 19(b). This increases the ink pressure,forcing ink 321 out of the nozzle 302, and causing the ink meniscus 316to bulge. The nozzle rim 303 prevents the ink meniscus 316 fromspreading across the surface of the nozzle chamber 304.

[0625] As the temperature of the beam pairs 308 and 309 equalizes, theactuator 320 returns to its original position. This aids in thebreak-off of the ink droplet 317 from the ink 321 in the nozzle chamber.The nozzle chamber is refilled by the action of the surface tension atthe meniscus 316.

[0626] In a netpage printer, the length of the printhead is the fullwidth of the paper (typically 210 mm). When printing, the paper is movedpast the fixed printhead. The printhead has 6 rows of interdigitatedprinting elements 300, printing the six colors or types of ink suppliedby the ink inlets.

[0627] To protect the fragile surface of the printhead during operation,a nozzle guard wafer is attached to the printhead substrate. For eachnozzle there is a corresponding nozzle guard hole through which the inkdroplets are fired. To prevent the nozzle guard holes from becomingblocked by paper fibers or other debris, filtered air is pumped throughthe air inlets and out of the nozzle guard holes during printing. Toprevent ink from drying, the nozzle guard is sealed while the printer isidle.

[0628] 1.6 The Netpage Pen

[0629] The active sensing device of the netpage system is typically apen 101, which, using its 25 embedded controller 134, is able to captureand decode IR position tags from a page via an image sensor. The imagesensor is a solid-state device provided with an appropriate filter topermit sensing at only near-infrared wavelengths. As described in moredetail below, the system is able to sense when the nib is in contactwith the surface, and the pen is able to sense tags at a sufficient rateto capture human handwriting (i.e. at 200 dpi or greater and 100 Hz orfaster). Information captured by the pen is encrypted and wirelesslytransmitted to the printer (or base station), the printer or basestation interpreting the data with respect to the (known) pagestructure.

[0630] The preferred embodiment of the netpage pen operates both as anormal marking ink pen and as a non-marking stylus. The marking aspect,however, is not necessary for using the netpage system as a browsingsystem, such as when it is used as an Internet interface. Each netpagepen is registered with the netpage system and has a unique pen ID 61.FIG. 23 shows the netpage pen class diagram, reflecting pen-relatedinformation maintained by a registration server 11 on the netpagenetwork.

[0631] When either nib is in contact with a netpage, the pen determinesits position and orientation relative to the page. The nib is attachedto a force sensor, and the force on the nib is interpreted relative to athreshold to indicate whether the pen is “up” or “down”. This allows ainteractive element on the page to be ‘clicked’ by pressing with the pennib, in order to request, say, information from a network. Furthermore,the force is captured as a continuous value to allow, say, the fulldynamics of a signature to be verified.

[0632] The pen determines the position and orientation of its nib on thenetpage by imaging, in the infrared spectrum, an area 193 of the page inthe vicinity of the nib. It decodes the nearest tag and computes theposition of the nib relative to the tag from the observed perspectivedistortion on the imaged tag and the known geometry of the pen optics.Although the position resolution of the tag may be low, because the tagdensity on the page is inversely proportional to the tag size, theadjusted position resolution is quite high, exceeding the minimumresolution required for accurate handwriting recognition.

[0633] Pen actions relative to a netpage are captured as a series ofstrokes. A stroke consists of a sequence of time-stamped pen positionson the page, initiated by a pen-down event and completed by thesubsequent pen-up event. A stroke is also tagged with the page ID 50 ofthe netpage whenever the page ID changes, which, under normalcircumstances, is at the commencement of the stroke.

[0634] Each netpage pen has a current selection 826 associated with it,allowing the user to perform copy and paste operations etc. Theselection is timestamped to allow the system to discard it after adefined time period. The current selection describes a region of a pageinstance. It consists of the most recent digital ink stroke capturedthrough the pen relative to the background area of the page. It isinterpreted in an application-specific manner once it is submitted to anapplication via a selection hyperlink activation.

[0635] Each pen has a current nib 824. This is the nib last notified bythe pen to the system. In the case of the default netpage pen describedabove, either the marking black ink nib or the non-marking stylus nib iscurrent. Each pen also has a current nib style 825. This is the nibstyle last associated with the pen by an application, e.g. in responseto the user selecting a color from a palette. The default nib style isthe nib style associated with the current nib. Strokes captured througha pen are tagged with the current nib style. When the strokes aresubsequently reproduced, they are reproduced in the nib style with whichthey are tagged.

[0636] Whenever the pen is within range of a printer with which it cancommunicate, the pen slowly flashes its “online” LED. When the pen failsto decode a stroke relative to the page, it momentarily activates its“error” LED. When the pen succeeds in decoding a stroke relative to thepage, it momentarily activates its “ok” LED.

[0637] A sequence of captured strokes is referred to as digital ink.Digital ink forms the basis for the digital exchange of drawings andhandwriting, for online recognition of handwriting, and for onlineverification of signatures.

[0638] The pen is wireless and transmits digital ink to the netpageprinter via a short-range radio link. The transmitted digital ink isencrypted for privacy and security and packetized for efficienttransmission, but is always flushed on a pen-up event to ensure timelyhandling in the printer.

[0639] When the pen is out-of-range of a printer it buffers digital inkin internal memory, which has a capacity of over ten minutes ofcontinuous handwriting. When the pen is once again within range of aprinter, it transfers any buffered digital ink.

[0640] A pen can be registered with any number of printers, but becauseall state data resides in netpages both on paper and on the network, itis largely immaterial which printer a pen is communicating with at anyparticular time.

[0641] A preferred embodiment of the pen is described in greater detailin Section 6 below, with reference to FIGS. 8 to 10.

[0642] 1.7 Netpage Interaction

[0643] The netpage printer 601 receives data relating to a stroke fromthe pen 101 when the pen is used to interact with a netpage 1. The codeddata 3 of the tags 4 is read by the pen when it is used to execute amovement, such as a stroke. The data allows the identity of theparticular page and associated interactive element to be determined andan indication of the relative positioning of the pen relative to thepage to be obtained. The indicating data is transmitted to the printer,where it resolves, via the DNS, the page ID 50 of the stroke into thenetwork address of the netpage page server 10 which maintains thecorresponding page instance 830. It then transmits the stroke to thepage server. If the page was recently identified in an earlier stroke,then the printer may already have the address of the relevant pageserver in its cache. Each netpage consists of a compact page layoutmaintained persistently by a netpage page server (see below). The pagelayout refers to objects such as images, fonts and pieces of text,typically stored elsewhere on the netpage network.

[0644] When the page server receives the stroke from the pen, itretrieves the page description to which the stroke applies, anddetermines which element of the page description the stroke intersects.It is then able to interpret the stroke in the context of the type ofthe relevant element.

[0645] A “click” is a stroke where the distance and time between the pendown position and the subsequent pen up position are both less than somesmall maximum. An object which is activated by a click typicallyrequires a click to be activated, and accordingly, a longer stroke isignored. The failure of a pen action, such as a “sloppy” click, toregister is indicated by the lack of response from the pen's “ok” LED.

[0646] There are two kinds of input elements in a netpage pagedescription: hyperlinks and form fields. Input through a form field canalso trigger the activation of an associated hyperlink.

[0647] 1.7.1 Hyperlinks

[0648] A hyperlink is a means of sending a message to a remoteapplication, and typically elicits a printed response in the netpagesystem.

[0649] A hyperlink element 844 identifies the application 71 whichhandles activation of the hyperlink, a link ID 54 which identifies thehyperlink to the application, an “alias required” flag which asks thesystem to include the user's application alias ID 65 in the hyperlinkactivation, and a description which is used when the hyperlink isrecorded as a favorite or appears in the user's history. The hyperlinkelement class diagram is shown in FIG. 29.

[0650] When a hyperlink is activated, the page server sends a request toan application somewhere on the network. The application is identifiedby an application ID 64, and the application ID is resolved in thenormal way via the DNS. There are three types of hyperlinks: generalhyperlinks 863, form hyperlinks 865, and selection hyperlinks 864, asshown in FIG. 30. A general hyperlink can implement a request for alinked document, or may simply signal a preference to a server. A formhyperlink submits the corresponding form to the application. A selectionhyperlink submits the current selection to the application. If thecurrent selection contains a single-word piece of text, for example, theapplication may return a single-page document giving the word's meaningwithin the context in which it appears, or a translation into adifferent language. Each hyperlink type is characterized by whatinformation is submitted to the application.

[0651] The corresponding hyperlink instance 862 records a transaction ID55 which can be specific to the page instance on which the hyperlinkinstance appears. The transaction ID can identify user-specific data tothe application, for example a “shopping cart” of pending purchasesmaintained by a purchasing application on behalf of the user.

[0652] The system includes the pen's current selection 826 in aselection hyperlink activation.

[0653] The system includes the content of the associated form instance868 in a form hyperlink activation, although if the hyperlink has its“submit delta” attribute set, only input since the last form submissionis included. The system includes an effective return path in allhyperlink activations.

[0654] A hyperlinked group 866 is a group element 838 which has anassociated hyperlink, as shown in FIG. 31. When input occurs through anyfield element in the group, the hyperlink 844 associated with the groupis activated. A hyperlinked group can be used to associate hyperlinkbehavior with a field such as a checkbox. It can also be used, inconjunction with the “submit delta” attribute of a form hyperlink, toprovide continuous input to an application. It can therefore be used tosupport a “blackboard” interaction model, i.e. where input is capturedand therefore shared as soon as it occurs.

[0655] 1.7.2 Forms

[0656] A form defines a collection of related input fields used tocapture a related set of inputs through a printed netpage. A form allowsa user to submit one or more parameters to an application softwareprogram running on a server.

[0657] A form 867 is a group element 838 in the document hierarchy. Itultimately contains a set of terminal field elements 839. A forminstance 868 represents a printed instance of a form. It consists of aset of field instances 870 which correspond to the field elements 845 ofthe form. Each field instance has an associated value 871, whose typedepends on the type of the corresponding field element. Each field valuerecords input through a particular printed form instance, i.e. throughone or more printed netpages. The form class diagram is shown in FIG.32.

[0658] Each form instance has a status 872 which indicates whether theform is active, frozen, submitted, void or expired. A form is activewhen first printed. A form becomes frozen once it is signed or once itsfreeze time is reached. A form becomes submitted once one of itssubmission hyperlinks has been activated, unless the hyperlink has its“submit delta” attribute set. A form becomes void when the user invokesa void form, reset form or duplicate form page command. A form expireswhen its specified expiry time is reached, i.e. when the time the formhas been active exceeds the form's specified lifetime. While the form isactive, form input is allowed. Input through a form which is not activeis instead captured in the background field 833 of the relevant pageinstance. When the form is active or frozen, form submission is allowed.Any attempt to submit a form when the form is not active or frozen isrejected, and instead elicits an form status report.

[0659] Each form instance is associated (at 59) with any form instancesderived from it, thus providing a version history. This allows all butthe latest version of a form in a particular time period to be excludedfrom a search.

[0660] All input is captured as digital ink. Digital ink 873 consists ofa set of timestamped stroke groups 874, each of which consists of a setof styled strokes 875. Each stroke consists of a set of timestamped penpositions 876, each of which also includes pen orientation and nibforce. The digital ink class diagram is shown in FIG. 33.

[0661] A field element 845 can be a checkbox field 877, a text field878, a drawing field 879, or a signature field 880. The field elementclass diagram is shown in FIG. 34. Any digital ink captured in a field'szone 58 is assigned to the field.

[0662] A checkbox field has an associated boolean value 881, as shown inFIG. 35. Any mark (a tick, a cross, a stroke, a fill zigzag, etc.)captured in a checkbox field's zone causes a true value to be assignedto the field's value.

[0663] A text field has an associated text value 882, as shown in FIG.36. Any digital ink 35 captured in a text field's zone is automaticallyconverted to text via online handwriting recognition, and the text isassigned to the field's value. Online handwriting recognition iswell-understood (see, for example, Tappert, C., C. Y. Suen and T.Wakahara, “The State of the Art in On-Line Handwriting Recognition”,IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol.12,No.8, August 1990, the contents of which are herein incorporated bycross-reference).

[0664] A signature field has an associated digital signature value 883,as shown in FIG. 37. Any digital ink captured in a signature field'szone is automatically verified with respect to the identity of the ownerof the pen, and a digital signature of the content of the form of whichthe field is part is generated and assigned to the field's value. Thedigital signature is generated using the pen user's private signaturekey specific to the application which owns the form. Online signatureverification is well-understood (see, for example, Plamondon, R. and G.Lorette, “Automatic Signature Verification and Writer Identification—TheState of the Art”, Pattern Recognition, Vol.22, No.2, 1989, the contentsof which are herein incorporated by cross-reference).

[0665] A field element is hidden if its “hidden” attribute is set. Ahidden field element does not have an input zone on a page and does notaccept input. It can have an associated field value which is included inthe form data when the form containing the field is submitted.

[0666] “Editing” commands, such as strike-throughs indicating deletion,can also be recognized in form fields.

[0667] Because the handwriting recognition algorithm works “online”(i.e. with access to the dynamics of the pen movement), rather than“offline” (i.e. with access only to a bitmap of pen markings), it canrecognize run-on discretely-written characters with relatively highaccuracy, without a writer-dependent training phase. A writer-dependentmodel of handwriting is automatically generated over time, however, andcan be generated up-front if necessary,

[0668] Digital ink, as already stated, consists of a sequence ofstrokes. Any stroke which starts in a particular element's zone isappended to that element's digital ink stream, ready for interpretation.Any stroke not appended to an object's digital ink stream is appended tothe background field's digital ink stream.

[0669] Digital ink captured in the background field is interpreted as aselection gesture. Circumscription of one or more objects is generallyinterpreted as a selection of the circumscribed objects, although theactual interpretation is application-specific.

[0670] Table 3 summarises these various pen interactions with a netpage.

[0671] The system maintains a current selection for each pen. Theselection consists simply of the most recent stroke captured in thebackground field. The selection is cleared after an inactivity timeoutto ensure predictable behavior.

[0672] The raw digital ink captured in every field is retained on thenetpage page server and is optionally transmitted with the form datawhen the form is submitted to the application. This allows theapplication to interrogate the raw digital ink should it suspect theoriginal conversion, such as the conversion of handwritten text. Thiscan, for example, involve human intervention at the application levelfor forms which fail certain application-specific consistency checks. Asan extension to this, the entire background area of a form can bedesignated as a drawing field. The application can then decide, on thebasis of the presence of digital ink outside the explicit fields of theform, to route the form to a human operator, on the assumption that theuser may have indicated amendments to the filled-in fields outside ofthose fields. TABLE 3 Summary of pen interactions with a netpage ObjectType Pen input Action Hyperlink General Click Submit action toapplication Form Click Submit form to application Selection Click Submitselection to application Form field Checkbox Any mark Assign true tofield Text Handwriting Convert digital ink to text; assign text to fieldDrawing Digital ink Assign digital ink to field Signature SignatureVerify digital ink signature; generate digital signature of form; assigndigital signature to field None — Circumscription Assign digital ink tocurrent selection

[0673]FIG. 38 shows a flowchart of the process of handling pen inputrelative to a netpage. The process consists of receiving (at 884) astroke from the pen; identifying (at 885) the page instance 830 to whichthe page ID 50 in the stroke refers; retrieving (at 886) the pagedescription 5; identifying (at 887) a formatted element 839 whose zone58 the stroke intersects; determining (at 888) whether the formattedelement corresponds to a field element, and if so appending (at 892) thereceived stroke to the digital ink of the field value 871, interpreting(at 893) the accumulated digital ink of the field, and determining (at894) whether the field is part of a hyperlinked group 866 and if soactivating (at 895) the associated hyperlink; alternatively determining(at 889) whether the formatted element corresponds to a hyperlinkelement and if so activating (at 895) the corresponding hyperlink;alternatively, in the absence of an input field or hyperlink, appending(at 890) the received stroke to the digital ink of the background field833; and copying (at 891) the received stroke to the current selection826 of the current pen, as maintained by the registration server.

[0674]FIG. 38a shows a detailed flowchart of step 893 in the processshown in FIG. 38, where the accumulated digital ink of a field isinterpreted according to the type of the field. The process consists ofdetermining (at 896) whether the field is a checkbox and (at 897)whether the digital ink represents a checkmark, and if so assigning (at898) a true value to the field value; alternatively determining (at 899)whether the field is a text field and if so converting (at 900) thedigital ink to computer text, with the help of the appropriateregistration server, and assigning (at 901) the converted computer textto the field value; alternatively determining (at 902) whether the fieldis a signature field and if so verifying (at 903) the digital ink as thesignature of the pen's owner, with the help of the appropriateregistration server, creating (at 904) a digital signature of thecontents of the corresponding form, also with the help of theregistration server and using the pen owner's private signature keyrelating to the corresponding application, and assigning (at 905) thedigital signature to the field value.

[0675] 1.7.3 Page Server Commands

[0676] A page server command is a command which is handled locally bythe page server. It operates directly on form, page and documentinstances.

[0677] A page server command 907 can be a void form command 908, aduplicate form command 909, a reset form command 910, a get form statuscommand 911, a duplicate page command 912, a reset page command 913, aget page status command 914, a duplicate document command 915, a resetdocument command 916, or a get document status command 917, as shown inFIG. 39.

[0678] A void form command voids the corresponding form instance. Aduplicate form command voids the corresponding form instance and thenproduces an active printed copy of the current form instance with fieldvalues preserved. The copy contains the same hyperlink transaction IDsas the original, and so is indistinguishable from the original to anapplication. A reset form command voids the corresponding form instanceand then produces an active printed copy of the form instance with fieldvalues discarded. A get form status command produces a printed report onthe status of the corresponding form instance, including who publishedit, when it was printed, for whom it was printed, and the form status ofthe form instance.

[0679] Since a form hyperlink instance contains a transaction ID, theapplication has to be involved in producing a new form instance. Abutton requesting a new form instance is therefore typically implementedas a hyperlink.

[0680] A duplicate page command produces a printed copy of thecorresponding page instance with the background field value preserved.If the page contains a form or is part of a form, then the duplicatepage command is interpreted as a duplicate form command. A reset pagecommand produces a printed copy of the corresponding page instance withthe background field value discarded. If the page contains a form or ispart of a form, then the reset page command is interpreted as a resetform command. A get page status command produces a printed report on thestatus of the corresponding page instance, including who published it,when it was printed, for whom it was printed, and the status of anyforms it contains or is part of.

[0681] The netpage logo which appears on every netpage is usuallyassociated with a duplicate page element.

[0682] When a page instance is duplicated with field values preserved,field values are printed in their native form, i.e. a checkmark appearsas a standard checkmark graphic, and text appears as typeset text. Onlydrawings and signatures appear in their original form, with a signatureaccompanied by a standard graphic indicating successful signatureverification.

[0683] A duplicate document command produces a printed copy of thecorresponding document instance with background field values preserved.If the document contains any forms, then the duplicate document commandduplicates the forms in the same way a duplicate form command does. Areset document command produces a printed copy of the correspondingdocument instance with background field values discarded. If thedocument contains any forms, then the reset document command resets theforms in the same way a reset form command does. A get document statuscommand produces a printed report on the status of the correspondingdocument instance, including who published it, when it was printed, forwhom it was printed, and the status of any forms it contains.

[0684] If the page server command's “on selected” attribute is set, thenthe command operates on the page identified by the pen's currentselection rather than on the page containing the command. This allows amenu of page server commands to be printed. If the target page doesn'tcontain a page server command element for the designated page servercommand, then the command is ignored.

[0685] An application can provide application-specific handling byembedding the relevant page server command element in a hyperlinkedgroup. The page server activates the hyperlink associated with thehyperlinked group rather than executing the page server command.

[0686] A page server command element is hidden if its “hidden” attributeis set. A hidden command element does not have an input zone on a pageand so cannot be activated directly by a user. It can, however, beactivated via a page server command embedded in a different page, ifthat page server command has its “on selected” attribute set.

[0687] 1.8 Standard Features of Netpages

[0688] In the preferred form, each netpage is printed with the netpagelogo at the bottom to indicate that it is a netpage and therefore hasinteractive properties. The logo also acts as a copy button. In mostcases pressing the logo produces a copy of the page. In the case of aform, the button produces a copy of the entire form. And in the case ofa secure document, such as a ticket or coupon, the button elicits anexplanatory note or advertising page.

[0689] The default single-page copy function is handled directly by therelevant netpage page server. Special copy functions are handled bylinking the logo button to an application.

[0690] 1.9 User Help System

[0691] In a preferred embodiment, the netpage printer has a singlebutton labelled “Help”. When pressed it elicits a single help page 46 ofinformation, including:

[0692] status of printer connection

[0693] status of printer consumables

[0694] top-level help menu

[0695] document function menu

[0696] top-level netpage network directory

[0697] The help menu provides a hierarchical manual on how to use thenetpage system.

[0698] The document function menu includes the following functions:

[0699] print a copy of a document

[0700] print a clean copy of a form

[0701] print the status of a document

[0702] A document function is initiated by selecting the document andthen pressing the button. The status of a document indicates whopublished it and when, to whom it was delivered, and to whom and when itwas subsequently submitted as a form.

[0703] The help page is obviously unavailable if the printer is unableto print. In this case the “error” light is lit and the user can requestremote diagnosis over the network.

[0704] 2 Personalized Publication Model

[0705] In the following description, news is used as a canonicalpublication example to illustrate personalization mechanisms in thenetpage system. Although news is often used in the limited sense ofnewspaper and newsmagazine news, the intended scope in the presentcontext is wider.

[0706] In the netpage system, the editorial content and the advertisingcontent of a news publication are personalized using differentmechanisms. The editorial content is personalized according to thereader's explicitly stated and implicitly captured interest profile. Theadvertising content is personalized according to the reader's localityand demographic.

[0707] 2.1 Editorial Personalization

[0708] A subscriber can draw on two kinds of news sources: those thatdeliver news publications, and those that deliver news streams. Whilenews publications are aggregated and edited by the publisher, newsstreams are aggregated either by a news publisher or by a specializednews aggregator. News publications typically correspond to traditionalnewspapers and newsmagazines, while news streams can be many and varied:a “raw” news feed from a news service, a cartoon strip, a freelancewriter's column, a friend's bulletin board, or the reader's own e-mail.

[0709] The netpage publication server supports the publication of editednews publications as well as the aggregation of multiple news streams.By handling the aggregation and hence the formatting of news streamsselected directly by the reader, the server is able to place advertisingon pages over which it otherwise has no editorial control.

[0710] The subscriber builds a daily newspaper by selecting one or morecontributing news publications, and creating a personalized version ofeach. The resulting daily editions are printed and bound together into asingle newspaper. The various members of a household typically expresstheir different interests and tastes by selecting different dailypublications and then customizing them.

[0711] For each publication, the reader optionally selects specificsections. Some sections appear daily, while others appear weekly. Thedaily sections available from The New York Times online, for example,include “Page One Plus”, “National”, “International”, “Opinion”,“Business”, “Arts/Living”, “Technology”, and “Sports”. The set ofavailable sections is specific to a publication, as is the defaultsubset.

[0712] The reader can extend the daily newspaper by creating customsections, each one drawing on any number of news streams. Customsections might be created for e-mail and friends' announcements(“Personal”), or for monitoring news feeds for specific topics (“Alerts”or “Clippings”).

[0713] For each section, the reader optionally specifies its size,either qualitatively (e.g. short, medium, or long), or numerically (i.e.as a limit on its number of pages), and the desired proportion ofadvertising, either qualitatively (e.g. high, normal, low, none), ornumerically (i.e. as a percentage).

[0714] The reader also optionally expresses a preference for a largenumber of shorter articles or a small number of longer articles. Eacharticle is ideally written (or edited) in both short and long forms tosupport this preference.

[0715] An article may also be written (or edited) in different versionsto match the expected sophistication of the reader, for example toprovide children's and adults' versions. The appropriate version isselected according to the reader's age. The reader can specify a“reading age” which takes precedence over their biological age.

[0716] The articles which make up each section are selected andprioritized by the editors, and each is assigned a useful lifetime. Bydefault they are delivered to all relevant subscribers, in priorityorder, subject to space constraints in the subscribers' editions.

[0717] In sections where it is appropriate, the reader may optionallyenable collaborative filtering. This is then applied to articles whichhave a sufficiently long lifetime. Each article which qualifies forcollaborative filtering is printed with rating buttons at the end of thearticle. The buttons can provide an easy choice (e.g. “liked” and“disliked”), making it more likely that readers will bother to rate thearticle.

[0718] Articles with high priorities and short lifetimes are thereforeeffectively considered essential reading by the editors and aredelivered to most relevant subscribers.

[0719] The reader optionally specifies a serendipity factor, eitherqualitatively (e.g. do or don't surprise me), or numerically. A highserendipity factor lowers the threshold used for matching duringcollaborative filtering. A high factor makes it more likely that thecorresponding section will be filled to the reader's specified capacity.A different serendipity factor can be specified for different days ofthe week.

[0720] The reader also optionally specifies topics of particularinterest within a section, and this modifies the priorities assigned bythe editors.

[0721] The speed of the reader's Internet connection affects the qualityat which images can be delivered. The reader optionally specifies apreference for fewer images or smaller images or both. If the number orsize of images is not reduced, then images may be delivered at lowerquality (i.e. at lower resolution or with greater compression).

[0722] At a global level, the reader specifies how quantities, dates,times and monetary values are localized. This involves specifyingwhether units are imperial or metric, a local timezone and time format,and a local currency, and whether the localization consist of in situtranslation or annotation. These preferences are derived from thereader's locality by default.

[0723] To reduce reading difficulties caused by poor eyesight, thereader optionally specifies a global preference for a largerpresentation. Both text and images are scaled accordingly, and lessinformation is accommodated on each page.

[0724] The language in which a news publication is published, and itscorresponding text encoding, is a property of the publication and not apreference expressed by the user. However, the netpage system can beconfigured to provide automatic translation services in various guises.

[0725] 2.2 Advertising Localization and Targeting

[0726] The personalization of the editorial content directly affects theadvertising content, because advertising is typically placed to exploitthe editorial context. Travel ads, for example, are more likely toappear in a travel section than elsewhere. The value of the editorialcontent to an advertiser (and therefore to the publisher) lies in itsability to attract large numbers of readers with the right demographics.

[0727] Effective advertising is placed on the basis of locality anddemographics. Locality determines proximity to particular services,retailers etc., and particular interests and concerns associated withthe local community and environment. Demographics determine generalinterests and preoccupations as well as likely spending patterns.

[0728] A news publisher's most profitable product is advertising“space”, a multi-dimensional entity determined by the publication'sgeographic coverage, the size of its readership, its readershipdemographics, and the page area available for advertising.

[0729] In the netpage system, the netpage publication server computesthe approximate multi-dimensional size of a publication's saleableadvertising space on a per-section basis, taking into account thepublication's geographic coverage, the section's readership, the size ofeach reader's section edition, each reader's advertising proportion, andeach reader's demographic.

[0730] In comparison with other media, the netpage system allows theadvertising space to be defined in greater detail, and allows smallerpieces of it to be sold separately. It therefore allows it to be sold atcloser to its true value.

[0731] For example, the same advertising “slot” can be sold in varyingproportions to several advertisers, with individual readers' pagesrandomly receiving the advertisement of one advertiser or another,overall preserving the proportion of space sold to each advertiser.

[0732] The netpage system allows advertising to be linked directly todetailed product information and online purchasing. It therefore raisesthe intrinsic value of the advertising space.

[0733] Because personalization and localization are handledautomatically by netpage publication servers, an advertising aggregatorcan provide arbitrarily broad coverage of both geography anddemographics. The subsequent disaggregation is efficient because it isautomatic. This makes it more cost-effective for publishers to deal withadvertising aggregators than to directly capture advertising. Eventhough the advertising aggregator is taking a proportion of advertisingrevenue, publishers may find the change profit-neutral because of thegreater efficiency of aggregation. The advertising aggregator acts as anintermediary between advertisers and publishers, and may place the sameadvertisement in multiple publications.

[0734] It is worth noting that ad placement in a netpage publication canbe more complex than ad placement in the publication's traditionalcounterpart, because the publication's advertising space is morecomplex. While ignoring the full complexities of negotiations betweenadvertisers, advertising aggregators and publishers, the preferred formof the netpage system provides some automated support for thesenegotiations, including support for automated auctions of advertisingspace. Automation is particularly desirable for the placement ofadvertisements which generate small amounts of income, such as small orhighly localized advertisements.

[0735] Once placement has been negotiated, the aggregator captures andedits the advertisement and records it on a netpage ad server.Correspondingly, the publisher records the ad placement on the relevantnetpage publication server. When the netpage publication server lays outeach user's personalized publication, it picks the relevantadvertisements from the netpage ad server.

[0736] 2.3 User Profiles

[0737] 2.3.1 Information Filtering

[0738] The personalization of news and other publications relies on anassortment of user-specific profile information, including:

[0739] publication customizations

[0740] collaborative filtering vectors

[0741] contact details

[0742] presentation preferences

[0743] The customization of a publication is typicallypublication-specific, and so the customization information is maintainedby the relevant netpage publication server.

[0744] A collaborative filtering vector consists of the user's ratingsof a number of news items. It is used to correlate different users'interests for the purposes of making recommendations. Although there arebenefits to maintaining a single collaborative filtering vectorindependently of any particular publication, there are two reasons whyit is more practical to maintain a separate vector for each publication:there is likely to be more overlap between the vectors of subscribers tothe same publication than between those of subscribers to differentpublications; and a publication is likely to want to present its users'collaborative filtering vectors as part of the value of its brand, notto be found elsewhere. Collaborative filtering vectors are thereforealso maintained by the relevant netpage publication server.

[0745] Contact details, including name, street address, ZIP Code, state,country, telephone numbers, are global by nature, and are maintained bya netpage registration server.

[0746] Presentation preferences, including those for quantities, datesand times, are likewise global and maintained in the same way.

[0747] The localization of advertising relies on the locality indicatedin the user's contact details, while the targeting of advertising relieson personal information such as date of birth, gender, marital status,income, profession, education, or qualitative derivatives such as agerange and income range.

[0748] For those users who choose to reveal personal information foradvertising purposes, the information is maintained by the relevantnetpage registration server. In the absence of such information,advertising can be targeted on the basis of the demographic associatedwith the user's ZIP or ZIP+4 Code.

[0749] Each user, pen, printer, application provider and application isassigned its own unique identifier, and the netpage registration servermaintains the relationships between them, as shown in FIGS. 21, 22, 23and 24. For registration purposes, a publisher is a special kind ofapplication provider, and a publication is a special kind ofapplication.

[0750] Each user 800 may be authorized to use any number of printers802, and each printer may allow any number of users to use it. Each userhas a single default printer (at 66), to which periodical publicationsare delivered by default, whilst pages printed on demand are deliveredto the printer through which the user is interacting. The server keepstrack of which publishers a user has authorized to print to the user'sdefault printer. A publisher does not record the ID of any particularprinter, but instead resolves the ID when it is required. The user mayalso be designated as having administrative privileges 69 on theprinter, allowing the user to authorize other users to use the printer.This only has meaning if the printer requires administrative privileges84 for such operations.

[0751] When a user subscribes 808 to a publication 807, the publisher806 (i.e. application provider 803) is authorized to print to aspecified printer or the user's default printer. This authorization canbe revoked at any time by the user. Each user may have several pens 801,but a pen is specific to a single user. If a user is authorized to use aparticular printer, then that printer recognizes any of the user's pens.

[0752] The pen ID is used to locate the corresponding user profilemaintained by a particular netpage registration server, via the DNS inthe usual way.

[0753] A Web terminal 809 can be authorized to print on a particularnetpage printer, allowing Web pages and netpage documents encounteredduring Web browsing to be conveniently printed on the nearest netpageprinter.

[0754] The netpage system can collect, on behalf of a printer provider,fees and commissions on income earned through publications printed onthe provider's printers. Such income can include advertising fees,click-through fees, e-commerce commissions, and transaction fees. If theprinter is owned by the user, then the user is the printer provider.

[0755] Each user also has a netpage account 820 which is used toaccumulate micro-debits and credits (such as those described in thepreceding paragraph); contact details 815, including name, address andtelephone numbers; global preferences 816, including privacy, deliveryand localization settings; any number of biometric records 817,containing the user's encoded signature 818, fingerprint 819 etc; ahandwriting model 819 automatically maintained by the system; and SETpayment card accounts 821, with which e-commerce payments can be made.

[0756] In addition to the user-specific netpage account, each user alsohas a netpage account 936 specific to each printer the user isauthorized to use. Each printer-specific account is used to accumulatemicro-debits and credits related to the user's activities on thatprinter. The user is billed on a regular basis for any outstanding debitbalances.

[0757] A user optionally appears in the netpage user directory 823,allowing other users to locate and direct e-mail (etc.) to the user.

[0758] 2.4 Intelligent Page Layout

[0759] The netpage publication server automatically lays out the pagesof each user's personalized publication on a section-by-section basis.Since most advertisements are in the form of pre-formatted rectangles,they are placed on the page before the editorial content.

[0760] The advertising ratio for a section can be achieved with wildlyvarying advertising ratios on individual pages within the section, andthe ad layout algorithm exploits this. The algorithm is configured toattempt to co-locate closely tied editorial and advertising content,such as placing ads for roofing material specifically within thepublication because of a special feature on do-it-yourself roofingrepairs.

[0761] The editorial content selected for the user, including text andassociated images and graphics, is then laid out according to variousaesthetic rules.

[0762] The entire process, including the selection of ads and theselection of editorial content, must be iterated once the layout hasconverged, to attempt to more closely achieve the user's stated sectionsize preference. The section size preference can, however, be matched onaverage over time, allowing significant day-to-day variations.

[0763] 2.5 Document Format

[0764] Once the document is laid out, it is encoded for efficientdistribution and persistent storage on the netpage network.

[0765] The primary efficiency mechanism is the separation of informationspecific to a single user's edition and information shared betweenmultiple users' editions. The specific information consists of the pagelayout. The shared information consists of the objects to which the pagelayout refers, including images, graphics, and pieces of text.

[0766] A text object contains fully-formatted text represented in theExtensible Markup Language (XML) using the Extensible StylesheetLanguage (XSL). XSL provides precise control over text formattingindependently of the region into which the text is being set, which inthis case is being provided by the layout. The text object containsembedded language codes to enable automatic translation, and embeddedhyphenation hints to aid with paragraph formatting.

[0767] An image object encodes an image in the JPEG 2000 wavelet-basedcompressed image format. A graphic object encodes a 2D graphic inScalable Vector Graphics (SVG) format.

[0768] The layout itself consists of a series of placed image andgraphic objects, linked textflow objects through which text objectsflow, hyperlinks and input fields as described above, and watermarkregions. These layout objects are summarized in Table 4. The layout usesa compact format suitable for efficient distribution and storage. TABLE4 netpage layout objects Layout Format of linked object Attribute objectImage Position — Image object ID JPEG 2000 Graphic Position — Graphicobject ID SVG Textflow Textflow ID — Zone — Optional text object IDXML/XSL Hyperlink Type — Zone — Application ID, etc. — Field Type —Meaning — Zone — Watermark Zone —

[0769] 2.6 Document Distribution

[0770] As described above, for purposes of efficient distribution andpersistent storage on the netpage network, a user-specific page layoutis separated from the shared objects to which it refers.

[0771] When a subscribed publication is ready to be distributed, thenetpage publication server allocates, with the help of the netpage IDserver 12, a unique ID for each page, page instance, document, anddocument instance.

[0772] The server computes a set of optimized subsets of the sharedcontent and creates a multicast channel for each subset, and then tagseach user-specific layout with the names of the multicast channels whichwill carry the shared content used by that layout. The server thenpointcasts each user's layouts to that user's printer via theappropriate page server, and when the pointcasting is complete,multicasts the shared content on the specified channels. After receivingits pointcast, each page server and printer subscribes to the multicastchannels specified in the page layouts. During the multicasts, each pageserver and printer extracts from the multicast streams those objectsreferred to by its page layouts. The page servers persistently archivethe received page layouts and shared content.

[0773] Once a printer has received all the objects to which its pagelayouts refer, the printer re-creates the fully-populated layout andthen rasterizes and prints it.

[0774] Under normal circumstances, the printer prints pages faster thanthey can be delivered. Assuming a quarter of each page is covered withimages, the average page has a size of less than 400 KB. The printer cantherefore hold in excess of 100 such pages in its internal 64 MB memory,allowing for temporary buffers etc. The printer prints at a rate of onepage per second. This is equivalent to 400 KB or about 3 Mbit of pagedata per second, which is similar to the highest expected rate of pagedata delivery over a broadband network.

[0775] Even under abnormal circumstances, such as when the printer runsout of paper, it is likely that the user will be able to replenish thepaper supply before the printer's 100-page internal storage capacity isexhausted.

[0776] However, if the printer's internal memory does fill up, then theprinter will be unable to make use of a multicast when it first occurs.The netpage publication server therefore allows printers to submitrequests for re-multicasts. When a critical number of requests isreceived or a timeout occurs, the server re-multicasts the correspondingshared objects.

[0777] Once a document is printed, a printer can produce an exactduplicate at any time by retrieving its page layouts and contents fromthe relevant page server.

[0778] 2.7 On-Demand Documents

[0779] When a netpage document is requested on demand, it can bepersonalized and delivered in much the same way as a periodical.However, since there is no shared content, delivery is made directly tothe requesting printer without the use of multicast.

[0780] When a non-netpage document is requested on demand, it is notpersonalized, and it is delivered via a designated netpage formattingserver which reformats it as a netpage document. A netpage formattingserver is a special instance of a netpage publication server. Thenetpage formatting server has knowledge of various Internet documentformats, including Adobe's Portable Document Format (PDF), and HypertextMarkup Language (HTML). In the case of HTML, it can make use of thehigher resolution of the printed page to present Web pages in amulti-column format, with a table of contents. It can automaticallyinclude all Web pages directly linked to the requested page. The usercan tune this behavior via a preference.

[0781] The netpage formatting server makes standard netpage behavior,including interactivity and persistence, available on any Internetdocument, no matter what its origin and format. It hides knowledge ofdifferent document formats from both the netpage printer and the netpagepage server, and hides knowledge of the netpage system from Web servers.

[0782] 2.8 ID Allocation

[0783] Unstructured netpage IDs such as the document ID 51, page ID(region ID) 50, etc., may be assigned on demand through a multi-levelassignment hierarchy with a single root node. Lower-level assignorsobtain blocks of IDs from higher-level assignors on demand. Unlike withstructured ID assignment, these blocks correspond to arbitrary ranges(or even sets) of IDs, rather than to IDs with fixed prefixes. Eachassignor in the assignment hierarchy ensures that blocks of IDs andindividual IDs are assigned uniquely.

[0784] Both registration servers 11 and ID servers 12 act as IDassignors.

[0785] 3 Security

[0786] 3.1 Cryptography

[0787] Cryptography is used to protect sensitive information, both instorage and in transit, and to authenticate parties to a transaction.There are two classes of cryptography in widespread use: secret-keycryptography and public-key cryptography. The netpage network uses bothclasses of cryptography.

[0788] Secret-key cryptography, also referred to as symmetriccryptography, uses the same key to encrypt and decrypt a message. Twoparties wishing to exchange messages must first arrange to securelyexchange the secret key.

[0789] Public-key cryptography, also referred to as asymmetriccryptography, uses two encryption keys. The two keys are mathematicallyrelated in such a way that any message encrypted using one key can onlybe decrypted using the other key. One of these keys is then published,while the other is kept private. The public key is used to encrypt anymessage intended for the holder of the private key. Once encrypted usingthe public key, a message can only be decrypted using the private key.Thus two parties can securely exchange messages without first having toexchange a secret key. To ensure that the private key is secure, it isnormal for the holder of the private key to generate the key pair.

[0790] Public-key cryptography can be used to create a digitalsignature. The holder of the private key can create a known hash of amessage and then encrypt the hash using the private key. Anyone can thenverify that the encrypted hash constitutes the “signature” of the holderof the private key with respect to that particular message by decryptingthe encrypted hash using the public key and verifying the hash againstthe message. If the signature is appended to the message, then therecipient of the message can verify both that the message is genuine andthat it has not been altered in transit.

[0791] To make public-key cryptography work, there has to be a way todistribute public keys which prevents impersonation. This is normallydone using certificates and certificate authorities. A certificateauthority is a trusted third party which authenticates the connectionbetween a public key and someone's identity. The certificate authorityverifies the person's identity by examining identity documents, and thencreates and signs a digital certificate containing the person's identitydetails and public key. Anyone who trusts the certificate authority canuse the public key in the certificate with a high degree of certaintythat it is genuine. They just have to verify that the certificate hasindeed been signed by the certificate authority, whose public key iswell-known.

[0792] In most transaction environments, public-key cryptography is onlyused to create digital signatures and to securely exchange secretsession keys. Secret-key cryptography is used for all other purposes.

[0793] In the following discussion, when reference is made to the securetransmission of information between a netpage printer and a server, whatactually happens is that the printer obtains the server's certificate,authenticates it with reference to the certificate authority, uses thepublic key-exchange key in the certificate to exchange a secret sessionkey with the server, and then uses the secret session key to encrypt themessage data. A session key, by definition, can have an arbitrarilyshort lifetime.

[0794] 3.2 Netpage Printer Security

[0795] Each netpage printer is assigned a pair of unique identifiers attime of manufacture which are stored in read-only memory in the printerand in the netpage registration server database. The first ID 62 ispublic and uniquely identifies the printer on the netpage network. Thesecond ID is secret and is used when the printer is first registered onthe network.

[0796] When the printer connects to the netpage network for the firsttime after installation, it creates a signature public/private key pair.It transmits the secret ID and the public key securely to the netpageregistration server. The server compares the secret ID against theprinter's secret ID recorded in its database, and accepts theregistration if the IDs match. It then creates and signs a certificatecontaining the printer's public ID and public signature key, and storesthe certificate in the registration database.

[0797] The netpage registration server acts as a certificate authorityfor netpage printers, since it has access to secret information allowingit to verify printer identity.

[0798] When a user subscribes to a publication, a record is created inthe netpage registration server database authorizing the publisher toprint the publication to the user's default printer or a specifiedprinter. Every document sent to a printer via a page server is addressedto a particular user and is signed by the publisher using thepublisher's private signature key. The page server verifies, via theregistration database, that the publisher is authorized to deliver thepublication to the specified user. The page server verifies thesignature using the publisher's public key, obtained from thepublisher's certificate stored in the registration database.

[0799] The netpage registration server accepts requests to add printingauthorizations to the database, so long as those requests are initiatedvia a pen registered to the printer.

[0800] 3.3 Netpage Pen Security

[0801] Each netpage pen is assigned a unique identifier at time ofmanufacture which is stored in read-only memory in the pen and in thenetpage registration server database. The pen ID 61 uniquely identifiesthe pen on the netpage network.

[0802] A netpage pen can “know” a number of netpage printers, and aprinter can “know” a number of pens. A pen communicates with a printervia a radio frequency signal whenever it is within range of the printer.Once a pen and printer are registered, they regularly exchange sessionkeys. Whenever the pen transmits digital ink to the printer, the digitalink is always encrypted using the appropriate session key. Digital inkis never transmitted in the clear.

[0803] A pen stores a session key for every printer it knows, indexed byprinter ID, and a printer stores a session key for every pen it knows,indexed by pen ID. Both have a large but finite storage capacity forsession keys, and will forget a session key on a least-recently-usedbasis if necessary.

[0804] When a pen comes within range of a printer, the pen and printerdiscover whether they know each other. If they don't know each other,then the printer determines whether it is supposed to know the pen. Thismight be, for example, because the pen belongs to a user who isregistered to use the printer. If the printer is meant to know the penbut doesn't, then it initiates the automatic pen registration procedure.If the printer isn't meant to know the pen, then it agrees with the pento ignore it until the pen is placed in a charging cup, at which time itinitiates the registration procedure.

[0805] In addition to its public ID, the pen contains a secretkey-exchange key. The key-exchange key is also recorded in the netpageregistration server database at time of manufacture. Duringregistration, the pen transmits its pen ID to the printer, and theprinter transmits the pen ID to the netpage registration server. Theserver generates a session key for the printer and pen to use, andsecurely transmits the session key to the printer. It also transmits acopy of the session key encrypted with the pen's key-exchange key. Theprinter stores the session key internally, indexed by the pen ID, andtransmits the encrypted session key to the pen. The pen stores thesession key internally, indexed by the printer ID.

[0806] Although a fake pen can impersonate a pen in the pen registrationprotocol, only a real pen can decrypt the session key transmitted by theprinter.

[0807] When a previously unregistered pen is first registered, it is oflimited use until it is linked to a user. A registered but “un-owned”pen is only allowed to be used to request and fill in netpage user andpen registration forms, to register a new user to which the new pen isautomatically linked, or to add a new pen to an existing user.

[0808] The pen uses secret-key rather than public-key encryption becauseof hardware performance constraints in the pen.

[0809] 3.4 Secure Documents

[0810] The netpage system supports the delivery of secure documents suchas tickets and coupons. The netpage printer includes a facility to printwatermarks, but will only do so on request from publishers who aresuitably authorized. The publisher indicates its authority to printwatermarks in its certificate, which the printer is able toauthenticate.

[0811] The “watermark” printing process uses an alternative dithermatrix in specified “watermark” regions of the page. Back-to-back pagescontain mirror-image watermark regions which coincide when printed. Thedither matrices used in odd and even pages' watermark regions aredesigned to produce an interference effect when the regions are viewedtogether, achieved by looking through the printed sheet.

[0812] The effect is similar to a watermark in that it is not visiblewhen looking at only one side of the page, and is lost when the page iscopied by normal means.

[0813] Pages of secure documents cannot be copied using the built-innetpage copy mechanism described in Section 1.9 above. This extends tocopying netpages on netpage-aware photocopiers.

[0814] Secure documents are typically generated as part of e-commercetransactions. They can therefore include the user's photograph which wascaptured when the user registered biometric information with the netpageregistration server, as described in Section 2.

[0815] When presented with a secure netpage document, the recipient canverify its authenticity by requesting its status in the usual way. Theunique ID of a secure document is only valid for the lifetime of thedocument, and secure document IDs are allocated non-contiguously toprevent their prediction by opportunistic forgers. A secure documentverification pen can be developed with built-in feedback on verificationfailure, to support easy point-of-presentation document verification.

[0816] Clearly neither the watermark nor the user's photograph aresecure in a cryptographic sense. They simply provide a significantobstacle to casual forgery. Online document verification, particularlyusing a verification pen, provides an added level of security where itis needed, but is still not entirely immune to forgeries.

[0817] 3.5 Non-Repudiation

[0818] In the netpage system, forms submitted by users are deliveredreliably to forms handlers and are persistently archived on netpage pageservers. It is therefore impossible for recipients to repudiatedelivery.

[0819] E-commerce payments made through the system, as described inSection 4, are also impossible for the payee to repudiate.

[0820] 4 Electronic Commerce Model

[0821] 4.1 Secure Electronic Transaction (SET)

[0822] The netpage system uses the Secure Electronic Transaction (SET)system as one of its payment systems. SET, having been developed byMasterCard and Visa, is organized around payment cards, and this isreflected in the terminology. However, much of the system is independentof the type of accounts being used.

[0823] In SET, cardholders and merchants register with a certificateauthority and are issued with certificates containing their publicsignature keys. The certificate authority verifies a cardholder'sregistration details with the card issuer as appropriate, and verifies amerchant's registration details with the acquirer as appropriate.Cardholders and merchants store their respective private signature keyssecurely on their computers. During the payment process, thesecertificates are used to mutually authenticate a merchant andcardholder, and to authenticate them both to the payment gateway.

[0824] SET has not yet been adopted widely, partly because cardholdermaintenance of keys and certificates is considered burdensome. Interimsolutions which maintain cardholder keys and certificates on a serverand give the cardholder access via a password have met with somesuccess.

[0825] 4.2 SET Payments

[0826] In the netpage system the netpage registration server acts as aproxy for the netpage user (i.e. the cardholder) in SET paymenttransactions.

[0827] The netpage system uses biometrics to authenticate the user andauthorize SET payments. Because the system is pen-based, the biometricused is the user's on-line signature, consisting of time-varying penposition and pressure. A fingerprint biometric can also be used bydesigning a fingerprint sensor into the pen, although at a higher cost.The type of biometric used only affects the capture of the biometric,not the authorization aspects of the system.

[0828] The first step to being able to make SET payments is to registerthe user's biometric with the netpage registration server. This is donein a controlled environment, for example a bank, where the biometric canbe captured at the same time as the user's identity is verified. Thebiometric is captured and stored in the registration database, linked tothe user's record. The user's photograph is also optionally captured andlinked to the record. The SET cardholder registration process iscompleted, and the resulting private signature key and certificate arestored in the database. The user's payment card information is alsostored, giving the netpage registration server enough information to actas the user's proxy in any SET payment transaction.

[0829] When the user eventually supplies the biometric to complete apayment, for example by signing a netpage order form, the printersecurely transmits the order information, the pen ID and the biometricdata to the netpage registration server. The server verifies thebiometric with respect to the user identified by the pen ID, and fromthen on acts as the user's proxy in completing the SET paymenttransaction.

[0830] 4.3 Micro-Payments

[0831] The netpage system includes a mechanism for micro-payments, toallow the user to be conveniently charged for printing low-costdocuments on demand and for copying copyright documents, and possiblyalso to allow the user to be reimbursed for expenses incurred inprinting advertising material. The latter depends on the level ofsubsidy already provided to the user.

[0832] When the user registers for e-commerce, a network account isestablished which aggregates micro-payments. The user receives astatement on a regular basis, and can settle any outstanding debitbalance using the standard payment mechanism.

[0833] The network account can be extended to aggregate subscriptionfees for periodicals, which would also otherwise be presented to theuser in the form of individual statements.

[0834] 4.4 Transactions

[0835] When a user requests a netpage in a particular applicationcontext, the application is able to embed a user-specific transaction ID55 in the page. Subsequent input through the page is tagged with thetransaction ID, and the application is thereby able to establish anappropriate context for the user's input.

[0836] When input occurs through a page which is not user-specific,however, the application must use the user's unique identity toestablish a context. A typical example involves adding items from apre-printed catalog page to the user's virtual “shopping cart”. Toprotect the user's privacy, however, the unique user ID 60 known to thenetpage system is not divulged to applications. This is to preventdifferent application providers from easily correlating independentlyaccumulated behavioral data.

[0837] The netpage registration server instead maintains an anonymousrelationship between a user and an application via a unique alias ID 65,as shown in FIG. 24. Whenever the user activates a hyperlink tagged withthe “registered” attribute, the netpage page server asks the netpageregistration server to translate the associated application ID 64,together with the pen ID 61, into an alias ID 65. The alias ID is thensubmitted to the hyperlink's application.

[0838] The application maintains state information indexed by alias ID,and is able to retrieve user-specific state information withoutknowledge of the global identity of the user.

[0839] The system also maintains an independent certificate and privatesignature key for each of a user's applications, to allow it to signapplication transactions on behalf of the user using onlyapplication-specific information.

[0840] To assist the system in routing product bar code (e.g. UPC) andsimilar product-item-related “hyperlink” activations, the system recordsa favorite application on behalf of the user for any number of producttypes. For example, a user may nominate Amazon as their favoritebookseller, while a different user may nominate Barnes and Noble. Whenthe first user requests book-related information, e.g. via a printedbook review or via an actual book, they are provided with theinformation by Amazon.

[0841] Each application is associated with an application provider, andthe system maintains an account on behalf of each application provider,to allow it to credit and debit the provider for click-through fees etc.

[0842] An application provider can be a publisher of periodicalsubscribed content. The system records the user's willingness to receivethe subscribed publication, as well as the expected frequency ofpublication.

[0843] 5 Communications Protocols

[0844] A communications protocol defines an ordered exchange of messagesbetween entities. In the netpage system, entities such as pens, printersand servers utilise a set of defined protocols to cooperatively handleuser interaction with the netpage system.

[0845] Each protocol is illustrated by way of a sequence diagram inwhich the horizontal dimension is used to represent message flow and thevertical dimension is used to represent time. Each entity is representedby a rectangle containing the name of the entity and a vertical columnrepresenting the lifeline of the entity. During the time an entityexists, the lifeline is shown as a dashed line. During the time anentity is active, the lifeline is shown as a double line. Because theprotocols considered here do not create or destroy entities, lifelinesare generally cut short as soon as an entity ceases to participate in aprotocol.

[0846] 5.1 Subscription Delivery Protocol

[0847] A preferred embodiment of a subscription delivery protocol isshown in FIG. 40.

[0848] A large number of users may subscribe to a periodicalpublication. Each user's edition may be laid out differently, but manyusers' editions will share common content such as text objects and imageobjects. The subscription delivery protocol therefore delivers documentstructures to individual printers via pointcast, but delivers sharedcontent objects via multicast.

[0849] The application (i.e. publisher) first obtains a document ID 51for each document from an ID server 12. It then sends each documentstructure, including its document ID and page descriptions, to the pageserver 10 responsible for the document's newly allocated ID. It includesits own application ID 64, the subscriber's alias ID 65, and therelevant set of multicast channel names. It signs the message using itsprivate signature key.

[0850] The page server uses the application ID and alias ID to obtainfrom the registration server the corresponding user ID 60, the user'sselected printer ID 62 (which may be explicitly selected for theapplication, or may be the user's default printer), and theapplication's certificate.

[0851] The application's certificate allows the page server to verifythe message signature. The page server's request to the registrationserver fails if the application ID and alias ID don't together identifya subscription 808.

[0852] The page server then allocates document and page instance IDs andforwards the page descriptions, including page IDs 50, to the printer.It includes the relevant set of multicast channel names for the printerto listen to.

[0853] It then returns the newly allocated page IDs to the applicationfor future reference.

[0854] Once the application has distributed all of the documentstructures to the subscribers' selected printers via the relevant pageservers, it multicasts the various subsets of the shared objects on thepreviously selected multicast channels. Both page servers and printersmonitor the appropriate multicast channels and receive their requiredcontent objects. They are then able to populate the previously pointcastdocument structures. This allows the page servers to add completedocuments to their databases, and it allows the printers to print thedocuments.

[0855] 5.2 Hyperlink Activation Protocol

[0856] A preferred embodiment of a hyperlink activation protocol isshown in FIG. 42.

[0857] When a user clicks on a netpage with a netpage pen, the pencommunicates the click to the nearest netpage printer 601. The clickidentifies the page and a location on the page. The printer alreadyknows the ID 61 of the pen from the pen connection protocol.

[0858] The printer determines, via the DNS, the network address of thepage server 10 a handling the particular page ID 50. The address mayalready be in its cache if the user has recently interacted with thesame page. The printer then forwards the pen ID, its own printer ID 62,the page ID and click location to the page server.

[0859] The page server loads the page description 5 identified by thepage ID and determines which input element's zone 58, if any, the clicklies in. Assuming the relevant input element is a hyperlink element 844,the page server then obtains the associated application ID 64 and linkID 54, and determines, via the DNS, the network address of theapplication server hosting the application 71.

[0860] The page server uses the pen ID 61 to obtain the correspondinguser ID 60 from the registration server 11, and then allocates aglobally unique hyperlink request ID 52 and builds a hyperlink request934. The hyperlink request class diagram is shown in FIG. 41. Thehyperlink request records the IDs of the requesting user and printer,and identifies the clicked hyperlink instance 862. The page server thensends its own server ID 53, the hyperlink request ID, and the link ID tothe application.

[0861] The application produces a response document according toapplication-specific logic, and obtains a document ID 51 from an IDserver 12. It then sends the document to the page server 10 bresponsible for the document's newly allocated ID, together with therequesting page server's ID and the hyperlink request ID.

[0862] The second page server sends the hyperlink request ID andapplication ID to the first page server to obtain the corresponding userID and printer ID 62. The first page server rejects the request if thehyperlink request has expired or is for a different application.

[0863] The second page server allocates document instance and page IDs50, returns the newly allocated page IDs to the application, adds thecomplete document to its own database, and finally sends the pagedescriptions to the requesting printer.

[0864] The hyperlink instance may include a meaningful transaction ID55, in which case the first page server includes the transaction ID inthe message sent to the application. This allows the application toestablish a transaction-specific context for the hyperlink activation.

[0865] If the hyperlink requires a user alias, i.e. its “alias required”attribute is set, then the first page server sends both the pen ID 61and the hyperlink's application ID 64 to the registration server 11 toobtain not just the user ID corresponding to the pen ID but also thealias ID 65 corresponding to the application ID and the user ID. Itincludes the alias ID in the message sent to the application, allowingthe application to establish a user-specific context for the hyperlinkactivation.

[0866] 5.3 Handwriting Recognition Protocol

[0867] When a user draws a stroke on a netpage with a netpage pen, thepen communicates the stroke to the nearest netpage printer. The strokeidentifies the page and a path on the page.

[0868] The printer forwards the pen ID 61, its own printer ID 62, thepage ID 50 and stroke path to the page server 10 in the usual way.

[0869] The page server loads the page description 5 identified by thepage ID and determines which input element's zone 58, if any, the strokeintersects. Assuming the relevant input element is a text field 878, thepage server appends the stroke to the text field's digital ink.

[0870] After a period of inactivity in the zone of the text field, thepage server sends the pen ID and the pending strokes to the registrationserver 11 for interpretation. The registration server identifies theuser corresponding to the pen, and uses the user's accumulatedhandwriting model 822 to interpret the strokes as handwritten text. Onceit has converted the strokes to text, the registration server returnsthe text to the requesting page server. The page server appends the textto the text value of the text field.

[0871] 5.4 Signature Verification Protocol

[0872] Assuming the input element whose zone the stroke intersects is asignature field 880, the page server 10 appends the stroke to thesignature field's digital ink.

[0873] After a period of inactivity in the zone of the signature field,the page server sends the pen ID 61 and the pending strokes to theregistration server 11 for verification. It also sends the applicationID 64 associated with the form of which the signature field is part, aswell as the form ID 56 and the current data content of the form. Theregistration server identifies the user corresponding to the pen, anduses the user's dynamic signature biometric 818 to verify the strokes asthe user's signature. Once it has verified the signature, theregistration server uses the application ID 64 and user ID 60 toidentify the user's application-specific private signature key. It thenuses the key to generate a digital signature of the form data, andreturns the digital signature to the requesting page server. The pageserver assigns the digital signature to the signature field and sets theassociated form's status to frozen.

[0874] The digital signature includes the alias ID 65 of thecorresponding user. This allows a single form to capture multiple users'signatures.

[0875] 5.5 Form Submission Protocol

[0876] A preferred embodiment of a form submission protocol is shown inFIG. 43.

[0877] Form submission occurs via a form hyperlink activation. It thusfollows the protocol defined in Section 5.2, with some form-specificadditions.

[0878] In the case of a form hyperlink, the hyperlink activation messagesent by the page server 10 to the application 71 also contains the formID 56 and the current data content of the form. If the form contains anysignature fields, then the application verifies each one by extractingthe alias ID 65 associated with the corresponding digital signature andobtaining the corresponding certificate from the registration server 11.

[0879] 6 Netpage Pen Description

[0880] 6.1 Pen Mechanics

[0881] Referring to FIGS. 8 and 9, the pen, generally designated byreference numeral 101, includes a housing 102 in the form of a plasticsmoulding having walls 103 defining an interior space 104 for mountingthe pen components. The pen top 105 is in operation rotatably mounted atone end 106 of the housing 102. A semi-transparent cover 107 is securedto the opposite end 108 of the housing 102. The cover 107 is also ofmoulded plastics, and is formed from semi-transparent material in orderto enable the user to view the status of the LED mounted within thehousing 102. The cover 107 includes a main part 109 which substantiallysurrounds the end 108 of the housing 102 and a projecting portion 110which projects back from the main part 109 and fits within acorresponding slot 111 formed in the walls 103 of the housing 102. Aradio antenna 112 is mounted behind the projecting portion 110, withinthe housing 102. Screw threads 113 surrounding an aperture 113A on thecover 107 are arranged to receive a metal end piece 114, includingcorresponding screw threads 115. The metal end piece 114 is removable toenable ink cartridge replacement.

[0882] Also mounted within the cover 107 is a tri-color status LED 116on a flex PCB 117. The antenna 112 is also mounted on the flex PCB 117.The status LED 116 is mounted at the top of the pen 101 for goodall-around visibility.

[0883] The pen can operate both as a normal marking ink pen and as anon-marking stylus. An ink pen cartridge 118 with nib 119 and a stylus120 with stylus nib 121 are mounted side by side within the housing 102.Either the ink cartridge nib 119 or the stylus nib 121 can be broughtforward through open end 122 of the metal end piece 114, by rotation ofthe pen top 105. Respective slider blocks 123 and 124 are mounted to theink cartridge 118 and stylus 120, respectively. A rotatable cam barrel125 is secured to the pen top 105 in operation and arranged to rotatetherewith. The cam barrel 125 includes a cam 126 in the form of a slotwithin the walls 181 of the cam barrel. Cam followers 127 and 128projecting from slider blocks 123 and 124 fit within the cam slot 126.On rotation of the cam barrel 125, the slider blocks 123 or 124 moverelative to each other to project either the pen nib 119 or stylus nib121 out through the hole 122 in the metal end piece 114. The pen 101 hasthree states of operation. By turning the top 105 through 90° steps, thethree states are:

[0884] stylus 120 nib 121 out

[0885] ink cartridge 118 nib 119 out, and

[0886] neither ink cartridge 118 nib 119 out nor stylus 120 nib 121 out

[0887] A second flex PCB 129, is mounted on an electronics chassis 130which sits within the housing 102. The second flex PCB 129 mounts aninfrared LED 131 for providing infrared radiation for projection ontothe surface. An image sensor 132 is provided mounted on the second flexPCB 129 for receiving reflected radiation from the surface. The secondflex PCB 129 also mounts a radio frequency chip 133, which includes anRF transmitter and RF receiver, and a controller chip 134 forcontrolling operation of the pen 101. An optics block 135 (formed frommoulded clear plastics) sits within the cover 107 and projects aninfrared beam onto the surface and receives images onto the image sensor132. Power supply wires 136 connect the components on the second flexPCB 129 to battery contacts 137 which are mounted within the cam barrel125. A terminal 138 connects to the battery contacts 137 and the cambarrel 125. A three volt rechargeable battery 139 sits within the cambarrel 125 in contact with the battery contacts. An induction chargingcoil 140 is mounted about the second flex PCB 129 to enable rechargingof the battery 139 via induction. The second flex PCB 129 also mounts aninfrared LED 143 and infrared photodiode 144 for detecting displacementin the cam barrel 125 when either the stylus 120 or the ink cartridge118 is used for writing, in order to enable a determination of the forcebeing applied to the surface by the pen nib 119 or stylus nib 121. TheIR photodiode 144 detects light from the IR LED 143 via reflectors (notshown) mounted on the slider blocks 123 and 124.

[0888] Rubber grip pads 141 and 142 are provided towards the end 108 ofthe housing 102 to assist gripping the pen 101, and top 105 alsoincludes a clip 142 for clipping the pen 101 to a pocket.

[0889] 6.2 Pen Controller

[0890] The pen 101 is arranged to determine the position of its nib(stylus nib 121 or ink cartridge nib 119) by imaging, in the infraredspectrum, an area of the surface in the vicinity of the nib. It recordsthe location data from the nearest location tag, and is arranged tocalculate the distance of the nib 121 or 119 from the location tabutilising optics 135 and controller chip 134. The controller chip 134calculates the orientation of the pen and the nib-to-tag distance fromthe perspective distortion observed on the imaged tag.

[0891] Utilising the RF chip 133 and antenna 112 the pen 101 cantransmit the digital ink data (which is encrypted for security andpackaged for efficient transmission) to the computing system.

[0892] When the pen is in range of a receiver, the digital ink data istransmitted as it is formed. When the pen 101 moves out of range,digital ink data is buffered within the pen 101 (the pen 101 circuitryincludes a buffer arranged to store digital ink data for approximately12 minutes of the pen motion on the surface) and can be transmittedlater.

[0893] The controller chip 134 is mounted on the second flex PCB 129 inthe pen 101. FIG. 10 is a block diagram illustrating in more detail thearchitecture of the controller chip 134. FIG. 10 also showsrepresentations of the RF chip 133, the image sensor 132, the tri-colorstatus LED 116, the IR illumination LED 131, the IR force sensor LED143, and the force sensor photodiode 144.

[0894] The pen controller chip 134 includes a controlling processor 145.Bus 146 enables the exchange of data between components of thecontroller chip 134. Flash memory 147 and a 512 KB DRAM 148 are alsoincluded. An analog-to-digital converter 149 is arranged to convert theanalog signal from the force sensor photodiode 144 to a digital signal.

[0895] An image sensor interface 152 interfaces with the image sensor132. A transceiver controller 153 and base band circuit 154 are alsoincluded to interface with the RF chip 133 which includes an RF circuit155 and RF resonators and inductors 156 connected to the antenna 112.

[0896] The controlling processor 145 captures and decodes location datafrom tags from the surface via the image sensor 132, monitors the forcesensor photodiode 144, controls the LEDs 116, 131 and 143, and handlesshort-range radio communication via the radio transceiver 153. It is amedium-performance (˜40 MHz) general-purpose RISC processor.

[0897] The processor 145, digital transceiver components (transceivercontroller 153 and baseband circuit 154), image sensor interface 152,flash memory 147 and 512 KB DRAM 148 are integrated in a singlecontroller ASIC. Analog RF components (RF circuit 155 and RF resonatorsand inductors 156) are provided in the separate RF chip.

[0898] The image sensor is a CCD or CMOS image sensor. Depending ontagging scheme, it has a size ranging from about 100×100 pixels to200×200 pixels. Many miniature CMOS image sensors are commerciallyavailable, including the National Semiconductor LM9630.

[0899] The controller ASIC 134 enters a quiescent state after a periodof inactivity when the pen 101 is not in contact with a surface. Itincorporates a dedicated circuit 150 which monitors the force sensorphotodiode 144 and wakes up the controller 134 via the power manager 151on a pen-down event.

[0900] The radio transceiver communicates in the unlicensed 900 MHz bandnormally used by cordless telephones, or alternatively in the unlicensed2.4 GHz industrial, scientific and medical (ISM) band, and usesfrequency hopping and collision detection to provide interference-freecommunication.

[0901] In an alternative embodiment, the pen incorporates an InfraredData Association (IrDA) interface for short-range communication with abase station or netpage printer.

[0902] In a further embodiment, the pen 101 includes a pair oforthogonal accelerometers mounted in the normal plane of the pen 101axis. The accelerometers 190 are shown in FIGS. 9 and 10 in ghostoutline.

[0903] The provision of the accelerometers enables this embodiment ofthe pen 101 to sense motion without reference to surface location tags,allowing the location tags to be sampled at a lower rate. Each locationtag ID can then identify an object of interest rather than a position onthe surface. For example, if the object is a user interface inputelement (e.g. a command button), then the tag ID of each location tagwithin the area of the input element can directly identify the inputelement.

[0904] The acceleration measured by the accelerometers in each of the xand y directions is integrated with respect to time to produce aninstantaneous velocity and position.

[0905] Since the starting position of the stroke is not known, onlyrelative positions within a stroke are calculated. Although positionintegration accumulates errors in the sensed acceleration,accelerometers typically have high resolution, and the time duration ofa stroke, over which errors accumulate, is short.

[0906] 7 Netpage Printer Description

[0907] 7.1 Printer Mechanics

[0908] The vertically-mounted netpage wallprinter 601 is shown fullyassembled in FIG. 11. It prints netpages on Letter/A4 sized media usingduplexed 8½″ Memjet™ print engines 602 and 603, as shown in FIGS. 12 and12a. It uses a straight paper path with the paper 604 passing throughthe duplexed print engines 602 and 603 which print both sides of a sheetsimultaneously, in full color and with full bleed.

[0909] An integral binding assembly 605 applies a strip of glue alongone edge of each printed sheet, allowing it to adhere to the previoussheet when pressed against it. This creates a final bound document 618which can range in thickness from one sheet to several hundred sheets.

[0910] The replaceable ink cartridge 627, shown in FIG. 13 coupled withthe duplexed print engines, has bladders or chambers for storingfixative, adhesive, and cyan, magenta, yellow, black and infrared inks.The cartridge also contains a micro air filter in a base molding. Themicro air filter interfaces with an air pump 638 inside the printer viaa hose 639. This provides filtered air to the printheads to preventingress of micro particles into the Memjet™ printheads 350 which mightotherwise clog the printhead nozzles. By incorporating the air filterwithin the cartridge, the operational life of the filter is effectivelylinked to the life of the cartridge. The ink cartridge is a fullyrecyclable product with a capacity for printing and gluing 3000 pages(1500 sheets).

[0911] Referring to FIG. 12, the motorized media pick-up roller assembly626 pushes the top sheet directly from the media tray past a papersensor on the first print engine 602 into the duplexed Memjet™ printheadassembly. The two Memjet™ print engines 602 and 603 are mounted in anopposing in-line sequential configuration along the straight paper path.The paper 604 is drawn into the first print engine 602 by integral,powered pick-up rollers 626. The position and size of the paper 604 issensed and full bleed printing commences. Fixative is printedsimultaneously to aid drying in the shortest possible time.

[0912] The paper exits the first Memjet™ print engine 602 through a setof powered exit spike wheels (aligned along the straight paper path),which act against a rubberized roller. These spike wheels contact the‘wet’ printed surface and continue to feed the sheet 604 into the secondMemjet™ print engine 603.

[0913] Referring to FIGS. 12 and 12a, the paper 604 passes from theduplexed print engines 602 and 603 into the binder assembly 605. Theprinted page passes between a powered spike wheel axle 670 with afibrous support roller and another movable axle with spike wheels and amomentary action glue wheel. The movable axle/glue assembly 673 ismounted to a metal support bracket and it is transported forward tointerface with the powered axle 670 via gears by action of a camshaft. Aseparate motor powers this camshaft.

[0914] The glue wheel assembly 673 consists of a partially hollow axle679 with a rotating coupling for the glue supply hose 641 from the inkcartridge 627. This axle 679 connects to a glue wheel, which absorbsadhesive by capillary action through radial holes. A molded housing 682surrounds the glue wheel, with an opening at the front. Pivoting sidemoldings and sprung outer doors are attached to the metal bracket andhinge out sideways when the rest of the assembly 673 is thrust forward.This action exposes the glue wheel through the front of the moldedhousing 682. Tension springs close the assembly and effectively cap theglue wheel during periods of inactivity.

[0915] As the sheet 604 passes into the glue wheel assembly 673,adhesive is applied to one vertical edge on the front side (apart fromthe first sheet of a document) as it is transported down into thebinding assembly 605.

[0916] 7.2 Printer Controller Architecture

[0917] The netpage printer controller consists of a controllingprocessor 750, a factory-installed or field-installed network interfacemodule 625, a radio transceiver (transceiver controller 753, basebandcircuit 754, RF circuit 755, and RF resonators and inductors 756), dualraster image processor (RIP) DSPs 757, duplexed print engine controllers760 a and 760 b, flash memory 658, and 64 MB of DRAM 657, as illustratedin FIG. 14.

[0918] The controlling processor handles communication with the network19 and with local wireless netpage pens 101, senses the help button 617,controls the user interface LEDs 613-616, and feeds and synchronizes theRIP DSPs 757 and print engine controllers 760. It consists of amedium-performance general-purpose microprocessor. The controllingprocessor 750 communicates with the print engine controllers 760 via ahigh-speed serial bus 659.

[0919] The RIP DSPs rasterize and compress page descriptions to thenetpage printer's compressed page format. Each print engine controllerexpands, dithers and prints page images to its associated Memjet™printhead 350 in real time (i.e. at over 30 pages per minute). Theduplexed print engine controllers print both sides of a sheetsimultaneously.

[0920] The master print engine controller 760 a controls the papertransport and monitors ink usage in conjunction with the master QA chip665 and the ink cartridge QA chip 761.

[0921] The printer controller's flash memory 658 holds the software forboth the processor 750 and the DSPs 757, as well as configuration data.This is copied to main memory 657 at boot time.

[0922] The processor 750, DSPs 757, and digital transceiver components(transceiver controller 753 and baseband circuit 754) are integrated ina single controller ASIC 656. Analog RF components (RF circuit 755 andRF resonators and inductors 756) are provided in a separate RF chip 762.The network interface module 625 is separate, since netpage printersallow the network connection to be factory-selected or field-selected.Flash memory 658 and the 2×256 Mbit (64 MB) DRAM 657 is also off-chip.The print engine controllers 760 are provided in separate ASICs.

[0923] A variety of network interface modules 625 are provided, eachproviding a netpage network interface 751 and optionally a localcomputer or network interface 752. netpage network Internet interfacesinclude POTS modems, Hybrid Fiber-Coax (HFC) cable modems, ISDN modems,DSL modems, satellite transceivers, current and next-generation cellulartelephone transceivers, and wireless local loop (WLL) transceivers.Local interfaces include IEEE 1284 (parallel port), 10Base-T and100Base-T Ethernet, USB and USB 2.0, IEEE 1394 (Firewire), and variousemerging home networking interfaces. If an Internet connection isavailable on the local network, then the local network interface can beused as the netpage network interface.

[0924] The radio transceiver 753 communicates in the unlicensed 900 MHzband normally used by cordless telephones, or alternatively in theunlicensed 2.4 GHz industrial, scientific and medical (ISM) band, anduses frequency hopping and collision detection to provideinterference-free communication.

[0925] The printer controller optionally incorporates an Infrared DataAssociation (IrDA) interface for receiving data “squirted” from devicessuch as netpage cameras. In an alternative embodiment, the printer usesthe IrDA interface for short-range communication with suitablyconfigured netpage pens.

[0926] 7.2.1 Rasterization and Printing

[0927] Once the main processor 750 has received and verified thedocument's page layouts and page objects, it runs the appropriate RIPsoftware on the DSPs 757.

[0928] The DSPs 757 rasterize each page description and compress therasterized page image. The main processor stores each compressed pageimage in memory. The simplest way to load-balance multiple DSPs is tolet each DSP rasterize a separate page. The DSPs can always be kept busysince an arbitrary number of rasterized pages can, in general, be storedin memory. This strategy only leads to potentially poor DSP utilizationwhen rasterizing short documents.

[0929] Watermark regions in the page description are rasterized to acontone-resolution bi-level bitmap which is losslessly compressed tonegligible size and which forms part of the compressed page image.

[0930] The infrared (IR) layer of the printed page contains codednetpage tags at a density of about six per inch. Each tag encodes thepage ID, tag ID, and control bits, and the data content of each tag isgenerated during rasterization and stored in the compressed page image.

[0931] The main processor 750 passes back-to-back page images to theduplexed print engine controllers 760. Each print engine controller 760stores the compressed page image in its local memory, and starts thepage expansion and printing pipeline. Page expansion and printing ispipelined because it is impractical to store an entire 114 MB bi-levelCMYK+IR page image in memory.

[0932] 7.2.2 Print Engine Controller

[0933] The page expansion and printing pipeline of the print enginecontroller 760 consists of a high speed IEEE 1394 serial interface 659,a standard JPEG decoder 763, a standard Group 4 Fax decoder 764, acustom halftoner/compositor unit 765, a custom tag encoder 766, a lineloader/formatter unit 767, and a custom interface 768 to the Memjet™printhead 350.

[0934] The print engine controller 360 operates in a double bufferedmanner. While one page is loaded into DRAM 769 via the high speed serialinterface 659, the previously loaded page is read from DRAM 769 andpassed through the print engine controller pipeline. Once the page hasfinished printing, the page just loaded is printed while another page isloaded.

[0935] The first stage of the pipeline expands (at 763) theJPEG-compressed contone CMYK layer, expands (at 764) the Group 4Fax-compressed bi-level black layer, and renders (at 766) the bi-levelnetpage tag layer according to the tag format defined in section 1.2,all in parallel. The second stage dithers (at 765) the contone CMYKlayer and composites (at 765) the bi-level black layer over theresulting bi-level CMYK layer. The resultant bi-level CMYK+IR dot datais buffered and formatted (at 767) for printing on the Memjet™ printhead350 via a set of line buffers. Most of these line buffers are stored inthe off-chip DRAM. The final stage prints the six channels of bi-leveldot data (including fixative) to the Memjet™ printhead 350 via theprinthead interface 768.

[0936] When several print engine controllers 760 are used in unison,such as in a duplexed configuration, they are synchronized via a sharedline sync signal 770. Only one print engine 760, selected via theexternal master/slave pin 771, generates the line sync signal 770 ontothe shared line.

[0937] The print engine controller 760 contains a low-speed processor772 for synchronizing the page expansion and rendering pipeline,configuring the printhead 350 via a low-speed serial bus 773, andcontrolling the stepper motors 675, 676.

[0938] In the 8½″ versions of the netpage printer, the two print engineseach prints 30 Letter pages per minute along the long dimension of thepage (11″), giving a line rate of 8.8 kHz at 1600 dpi. In the 12″versions of the netpage printer, the two print engines each prints 45Letter pages per minute along the short dimension of the page (8½″),giving a line rate of 10.2 kHz. These line rates are well within theoperating frequency of the Memjet™ printhead, which in the currentdesign exceeds 30 kHz.

[0939] 8 Product Tagging

[0940] Automatic identification refers to the use of technologies suchas bar codes, magnetic stripe cards, smartcards, and RF transponders, to(semi-)automatically identify objects to data processing systems withoutmanual keying. Existing systems typically utilise RFID tags ortwo-dimensional bar codes as discussed above.

[0941] However, significant problems exist with such systems and it istherefore proposed to provide tags utilising the netpage tagging system,herein after referred to as Hyperlabel™ tagging.

[0942] 8.1 Hyperlabel™ Tagging in the Supply Chain

[0943] Using an invisible (e.g. Infrared) tagging scheme such as thenetpage tagging scheme described above to uniquely identify a productitem has the significant advantage that it allows the entire surface ofa product to be tagged, or a significant portion thereof, withoutimpinging on the graphic design of the product's packaging or labelling.If the entire product surface is tagged, then the orientation of theproduct doesn't affect its ability to be scanned, i.e. a significantpart of the line-of-sight disadvantage of a visible bar code iseliminated. Furthermore, since the tags are small and massivelyreplicated, label damage no longer prevents scanning.

[0944] Hyperlabel™ tagging, then, consists of covering a largeproportion of the surface of a product item with optically-readableinvisible tags. When the tags utilise reflection or absorption in theinfrared spectrum they are also referred to as infrared identification(RID) tags. Each Hyperlabel™ tag uniquely identifies the product item onwhich it appears. The Hyperlabel™ tag may directly encode the productcode (e.g. EPC) of the item, or may encode a surrogate ID which in turnidentifies the product code via a database lookup. Each Hyperlabel™ tagalso optionally identifies its own position on the surface of theproduct item, to provide the downstream consumer benefits of netpageinteractivity described earlier.

[0945] Hyperlabel™ tags are applied during product manufacture and/orpackaging using digital printers. These may be add-on infrared printerswhich print the Hyperlabel™ tags after the text and graphics have beenprinted by other means, or integrated color and infrared printers whichprint the Hyperlabel™ tags, text and graphics simultaneously.Digitally-printed text and graphics may include everything on the labelor packaging, or may consist only of the variable portions, with otherportions still printed by other means.

[0946] The economic case for IRID Hyperlabel™ tagging is discussed inmore detail below.

[0947] 8.2 Hyperlabel™ Tagging

[0948] As shown in FIG. 18, a product's unique item ID 215 may be seenas a special kind of unique object ID 210. The Electronic Product Code(EPC) 220 is one emerging standard for an item ID. An item ID typicallyconsists of a product ID 214 and a serial number 213. The product IDidentifies a class of product, while the serial number identifies aparticular instance of that class, i.e. an individual product item. Theproduct ID in turn typically consists of a manufacturer number 211 and aproduct class number 212. The best-known product ID is the EAN.UCCUniversal Product Code (UPC) 221 and its variants.

[0949] As shown in FIG. 19, a Hyperlabel™ tag 202 encodes a page ID (orregion ID) 50 and a two-dimensional (2D) position 86. The region IDidentifies the surface region containing the tag, and the positionidentifies the tag's position within the two-dimensional region. Sincethe surface in question is the surface of a physical product item 201,it is useful to define a one-to-one mapping between the region ID andthe unique object ID 210, and more specifically the item ID 215, of theproduct item. Note, however, that the mapping can be many-to-one withoutcompromising the utility of the Hyperlabel™ tag. For example, each panelof a product item's packaging could have a different region ID 50.Conversely, the Hyperlabel™ tag may directly encode the item ID, inwhich case the region ID contains the item ID, suitably prefixed todecouple item ID allocation from general netpage region ID allocation.Note that the region ID uniquely distinguishes the corresponding surfaceregion from all other surface regions identified within the globalnetpage system. Directly encoding the item ID 215 in the region ID 50 ispreferred, since it allows the item ID to be obtained directly from theHyperlabel™ tag without additional lookup, thus facilitating moreseamless integration with inventory systems and the like.

[0950] The item ID 215 is preferably the EPC 220 proposed by the Auto-IDCenter, since this provides direct compatibility between Hyperlabel™tags and EPC-carrying RFID tags.

[0951] In FIG. 19 the position 86 is shown as optional. This is toindicate that much of the utility of the Hyperlabel™ tag in the supplychain derives from the region ID 50, and the position may be omitted ifnot desired for a particular product.

[0952] For interoperability with the netpage system, a Hyperlabel™ tag202 is a netpage tag 4, i.e. it has the logical structure, physicallayout and semantics of a netpage tag.

[0953] In one example, when a netpage sensing device such as the netpagepen 101 images and decodes a Hyperlabel™ tag, it uses the position andorientation of the tag in its field of view to compute its own positionrelative to the tag, and it combines this with the position encoded inthe tag, to compute its own position relative to the region containingthe tag. As the sensing device is moved relative to a Hyperlabel™ taggedsurface region, it is thereby able to track its own motion relative tothe region and generate a set of timestamped position samplesrepresentative of its time-varying path. When the sensing device is apen, then the path consists of a sequence of strokes, with each strokestarting when the pen makes contact with the surface, and ending whenthe pen breaks contact with the surface.

[0954] When a stroke is forwarded to the page server 10 responsible forthe region ID, the server retrieves a description of the region keyed byregion ID, and interprets the stroke in relation to the description. Forexample, if the description includes a hyperlink and the strokeintersects the zone of the hyperlink, then the server may interpret thestroke as a designation of the hyperlink and activate the hyperlink.

[0955] 8.2.1 Item ID Management

[0956] As previously described, a structured item ID 215 typically has athree-level encoding, consisting of a manufacturer number 211, a productclass number 212, and a serial number 213. In the EPC the manufacturernumber corresponds to the manager ID. Manufacturer numbers are assignedto particular manufacturers 235 by a governing body such as EAN,EPCglobal (UCC). Within the scope of each manufacturer number themanufacturer 235 assigns product class numbers to particular productclasses 236, and within the scope of each product class number themanufacturer assigns serial numbers to individual product items 237.Each assignor in the assignment hierarchy ensures that each component ofthe item ID is assigned uniquely, with the end result that an item IDuniquely identifies a single product item. Each assigned item IDcomponent is robustly recorded to ensure unique assignment, andsubsequently becomes a database key to details about the correspondingmanufacturer, product or item. At the product level this information mayinclude the product's description, dimensions, weight and price, whileat the item level it may include the item's expiry date and place ofmanufacture.

[0957] As shown in FIG. 20, a collection of related product classes maybe recorded as a single product type 238, identified by a unique producttype ID 217. This provides the basis for mapping a scanned or otherwiseobtained product ID 214 (or the product ID portion of a scanned orotherwise obtained item ID 215) to a product type 238. This in turnallows a favorite application 828 for that product type to be identifiedfor a particular netpage user 800, as shown in FIG. 24.

[0958] As a product item moves through the supply chain, statusinformation is ideally maintained in a globally accessible database,keyed by the item ID. This information may include the item's dynamicposition in the packaging, shipping and transportation hierarchy, itslocation on a store shelf, and ultimately the date and time of its saleand the recipient of that sale. In a packaging, shipping andtransportation hierarchy, higher level units such as cases, pallets,shipping containers and trucks all have their own item IDs, and thisprovides the basis for recording the dynamic hierarchy in which the endproduct item participates. Note that the concept of an item also extendsto a sub-component of an assembly or a component or element of asaleable product.

[0959]FIG. 20 shows the product description hierarchy corresponding tothe structure of the item ID; the product item's dynamic participationin a dynamic packaging, shipping and transportation hierarchy; and theproduct item's dynamic ownership. As the figure shows, a container 231(e.g. case, pallet, shipping container, or truck) is a special case ofan uniquely identified object 230. The fact that the container isholding, or has held, a particular object for the duration of some timeinterval is represented by the time-stamped object location 234, whereinthe end time remains unspecified until the container ceases to hold theitem. The object-container relationship is recursive, allowing it torepresent an arbitrary dynamic hierarchy. Clearly this representationcan be expanded to record the time-varying relative or absolutegeographic location of an object.

[0960] The fact that an entity 232 owns, or has owned, a particularobject for the duration of some time interval is represented by thetime-stamped object ownership 233, wherein the end time remainsunspecified until the entity ceases to own the item. The owning entity232 may represent a netpage user 800, e.g. when a netpage user purchasesa product item and the sale is recorded, or some other supply chainparticipant such as a manufacturer, distributor or retailer.

[0961] As shown in FIG. 56, a physical product item 201 is recorded as aproduct item 237 by a product server 251. A product item may be recordedin multiple product servers, managed by different participants in thesupply chain such as manufacturers, distributors and retailers. However,benefits accrue from providing a unified view of a product item, even ifthe unified view is provided virtually.

[0962] To foster interoperability between different supply chainparticipants and between disparate systems which may want to query andupdate both static and dynamic item information, such informationinterchanges are ideally performed using a standard representation. TheMIT Auto-ID Center's Physical Markup Language (PML) is an example of astandard representation designed for this purpose. For a detaileddescription of PML, refer to Brock, D. L. et al., The Physical MarkupLanguage, MIT Auto-ID Center (June 2001), the contents of which areherein incorporated by cross-reference.

[0963] The Auto-ID Centre has proposed a distributed architecturewherein a relevant supply chain participants are notified of productmovements in an event-driven manner.

[0964] In general there is a single public source of information aboutan item identified by an item ID, and there is a mechanism whichresolves an item ID into the network address of a corresponding server.In the case of an EPC, the ONS resolver rewrites the EPC into the domainname of the product server, and then uses the Domain Name System (DNS)to resolve the domain name into the address of the product server. TheDNS allows a domain name to resolve to a list of addresses, providing abasis for both load balancing and fault tolerance. DNS lookups are madeefficient by caching of results.

[0965] 8.2.2 EPC-Driven Supply Chain Example

[0966] In a supply chain driven by EPC scan data, legacy databasesystems will typically be enhanced to support the description andtracking of EPC-tagged containers and product items. Some scan eventsresult in message flow between systems, while other scan events resultin purely local database updates.

[0967] The EPC administrator (EPCglobal) allocates an EPC manager numberto the manufacturer for the exclusive use of a manufacturer. Themanufacturer in turn allocates an object class number to each of itsproducts. When the manufacturer produces a batch of a particularproduct, it allocates each product item a unique serial number withinthe corresponding object class, and encodes the entire EPC in theHyperlabel™ tags printed on the product item's label or packaging. Asthe manufacturer aggregates individual product items into cases andhigher-level containers, its manufacturing and shipping systems recordthe container hierarchy. This allows the contents of a container to betracked by simply tracking the container.

[0968] When a retailer receives a case, it is scanned into inventory atthe receiving dock. The scan event triggers the retailer's inventorysystem to retrieve a description of the case content from themanufacturer. The inventory system uses the case EPC to first identify,via the ONS, the server responsible for serving information about thatEPC. It then contacts that server to identify the contents of the case,and iterates the entire process for the case content, down to the itemlevel. In order to satisfy the inventory system's queries, themanufacturer's server extracts information from the manufacturer'sprivate databases and translates this information into standard PML.

[0969] When an item is sold, the point-of-sale EPC scan event triggersthe inventory system to record the item as sold, and may also triggerthe system to notify the item's manufacturer of the circumstances of thesale. This can provide the manufacturer with timely information aboutthe effect of a promotional campaign, particularly when the campaign islot-specific and involves campaign-specific product graphics. Again theEPC lookup uses the ONS, but this time the inventory system transmitsthe sale event information to the manufacturer's server as PML.

[0970] The EPC-driven architecture of the integrated supply chain isindependent of whether EPC scan data originates from Hyperlabel™scanners, RFID readers, or a mixture of both.

[0971] 8.2.3 Region Id Management

[0972] An unstructured identifier such as the region ID (page ID) may beassigned on demand through a multi-level assignment hierarchy with asingle root node. Lower-level assignors obtain blocks of IDs fromhigher-level assignors on demand. Unlike with structured ID assignment,these blocks correspond to arbitrary ranges (or even sets) of IDs,rather than to IDs with fixed prefixes. Again, each assignor in theassignment hierarchy ensures that blocks of IDs and individual IDs areassigned uniquely. The region ID subsequently becomes a database key toinformation about the region. In the netpage system, this informationincludes a full description of the graphical and interactive elementswhich appear in the region. Graphical elements include such things astext flows, text and images. Interactive elements include such things asbuttons, hyperlinks, checkboxes, drawing fields, text fields andsignature fields.

[0973] 8.2.4 Product Interface Document Management

[0974] In the netpage system, the graphic and interactive elements of anetpage are described by a document 836, as illustrated in FIG. 25. Aproduct manufacturer therefore defines the graphic and interactiveelements of a Hyperlabel™ tagged product item by publishing acorresponding interface document to the netpage system in much the usualway (i.e. as described earlier). The manufacturing application (i.e.publisher) first obtains a document ID 51 for the interface documentfrom an ID server 12. It then sends the document structure, includingits document ID and page descriptions, to the page server 10 responsiblefor the document's newly allocated ID.

[0975] Even if the graphic elements of a product label are printed bytraditional non-digital means (e.g. offset or flexographic), it is stillbeneficial to include the graphic elements in the netpage document 836,since this facilitates logical operations on otherwise passive labelcontent, such as copy and paste, and searching on a combination of labelcontent and annotations.

[0976] As described earlier, the preferred form of the region ID 50 of aHyperlabel™ tag 202 contains the corresponding item ID 215. When themanufacturer allocates an item ID to a product item at time ofmanufacture, the item ID is registered as a page ID with the page serverresponsible for the corresponding document 836. The page server recordsthe page ID as part of a page instance 830. The item ID is alsoregistered as a page ID with a netpage ID server to facilitatesubsequent lookup of the corresponding page server.

[0977] The document 836 typically describes the label or packaging of aclass 236 of product items. Publication of the document, down to thelevel of the formatted document 834, may therefore be decoupled from theprinting of individual product item labels. However, since the item ID215 is structured, the ID server and page server may also record apartial page ID based on an item ID 215 with a unspecified serial number213 (i.e. a product ID 214). When a netpage user interacts with anindividual product item, the relay function identifies the correspondingpage server via the ID server based purely on the product item's productID. If no page instance 830 exists which corresponds to the full item ID(i.e. page ID) then the page server creates a page instance againstwhich to record the interaction.

[0978] To address the situation where the label or packaging of aproduct class 236 changes over time, the ID server may record a range ofitem IDs against a document ID (e.g. in the form of a product ID and arange of serial numbers). The manufacturer may leave the end of therange unspecified until a label or packaging change actually occurs.

[0979] An individual item ID is already recorded by the product server237 which manages the product item. Therefore, as an alternative tousing the netpage ID server to record and support the lookup of thenetpage page server associated with an item ID, the page server caninstead be registered with the product server in much the same way.

[0980] Rather than publish an interface document to a netpage pageserver, the product server may instead allow the page server to retrievethe interface document from the product server on demand. The productserver is then responsible for recording relationships between ranges ofitem IDs and particular interface descriptions, as shown in FIG. 98. Asdescribed earlier, the page server may use a standard name servicelookup mechanism to resolve an item ID into a network address of acorresponding product server.

[0981]FIG. 99 shows a typical interaction between a netpage pen 101 anda Web server in this scenario. The pen 101 captures an item ID anddigital ink via a product surface. It forwards this to the netpage penserver associated with the pen. The pen server uses the item ID to lookup the address of the item ID's product server via a name server (orhierarchy of name servers). The pen server then retrieves the product'sinterface description from the identified product server, and uses theinterface description to interpret the user's digital ink input in theusual way. This may ultimately result in the submission of a form to,and/or the retrieval of a Web page from a Web server identified by a URIassociated with a form or hyperlink in the interface description. Againthis involves the resolution of a server address for the Web serverusing a name server, which is not shown in the figure. The pen servermay then display the Web page on a Web terminal associated with thenetpage pen. For example, the relay device (e.g. PC, mobile phone orPDA) through which the pen is communicating with the pen server may actas a Web terminal by running a Web browser. The user may continue tointeract with the Web page directly through the Web browser.

[0982] Note that in this scenario the page server has been replaced by apen server. Where the page server provides persistent storage of digitalink associated with particular pages, the pen server provides persistentstorage of digital ink associated with particular users' pens. In bothcases the persistence is provided at least until the form to which thedigital ink applies is submitted. Note that the pen server may be ashared network server which serves many users, or may be a privateserver which executes on the pen user's relay device (e.g. PC, mobiletelephone or PDA). In the limit case it may execute in the pen itself.

[0983] In the example described above, when the pen server uses the itemID to look up the address of the item ID's product server, this can beachieved by resolving the item ID to a product server address on thebasis of any or all of the manufacturer number 211, the product classnumber 212, and the serial number 213.

[0984] It will also be appreciated that the Web server scenariodescribed above is only one example of the general interaction between apen, a pen server, a name server, a product server and an application,which in this case is a Web server.

[0985] It will also be appreciated that the interaction between a penand application shown in FIG. 42, between the pen 101 (via the printeror other relay shown in the figure), a page server 10 a, and anapplication 71, if the manufacturer lodges interface descriptions with apage server, rather than providing interface descriptions directly ondemand to a pen server.

[0986] 8.3 Hyperlabel™ Tag Printing

[0987] A Hyperlabel™ printer is a digital printer which printsHyperlabel™ tags onto the label, packaging or actual surface of aproduct before, during or after product manufacture and/or assembly. Itis a special case of a netpage printer 601. It is capable of printing acontinuous pattern of Hyperlabel™ tags onto a surface, typically using anear-infrared-absorptive ink. In high-speed environments, the printerincludes hardware which accelerates tag rendering. This typicallyincludes real-time Reed-Solomon encoding of variable tag data such astag position, and real-time template-based rendering of the actual tagpattern at the dot resolution of the printhead.

[0988] The printer may be an add-on infrared printer which prints theHyperlabel™ tags after text and graphics have been printed by othermeans, or an integrated color and infrared printer which prints theHyperlabel™ tags, text and graphics simultaneously. Digitally-printedtext and graphics may include everything on the label or packaging, ormay consist only of the variable portions, with other portions stillprinted by other means. Thus a Hyperlabel™ tag printer with an infraredand black printing capability can displace an existing digital printerused for variable data printing, such as a conventional thermal transferor inkjet printer.

[0989] For the purposes of the following discussion, any reference toprinting onto an item label is intended to include printing onto theitem packaging in general, or directly onto the item surface.Furthermore, any reference to an item ID 215 is intended to include aregion ID 50 (or collection of per-panel region IDs), or a componentthereof.

[0990] The printer is typically controlled by a host computer, whichsupplies the printer with fixed and/or variable text and graphics aswell as item IDs for inclusion in the Hyperlabel™ tags. The host mayprovide real-time control over the printer, whereby it provides theprinter with data in real time as printing proceeds. As an optimisation,the host may provide the printer with fixed data before printing begins,and only provide variable data in real time. The printer may also becapable of generating per-item variable data based on parametersprovided by the host. For example, the host may provide the printer witha base item ID prior to printing, and the printer may simply incrementthe base item ID to generate successive item IDs. Alternatively, memoryin the ink cartridge or other storage medium inserted into the printermay provide a source of unique item IDs, in which case the printerreports the assignment of items IDs to the host computer for recordingby the host.

[0991] Alternatively still, the printer may be capable of reading apre-existing item ID from the label onto which the Hyperlabel™ tags arebeing printed, assuming the unique ID has been applied in some form tothe label during a previous manufacturing step. For example, the item IDmay already be present in the form of a visible 2D bar code, or encodedin an RFID tag. In the former case the printer can include an opticalbar code scanner, examples of which are described in U.S. Pat. No.5,340,973, or U.S. Pat. No. 5,126,544. In the latter case it can includean RFID reader, such as the reader described in U.S. Pat. No. 5,280,159,or such as a Commander 320 13.56 MHz RFID reader, manufactured by TexasInstruments of Dallas, Tex.

[0992] The printer may also be capable of rendering the item ID in otherforms. For example, it may be capable of printing the item ID in theform of a 2D bar code, or of printing the product ID component of theitem ID in the form of a ID bar code, or of writing the item ID to awritable or write-once RFID tag, for example by using the Commander 32013.56 MHz RFID reader, manufactured by Texas Instruments of Dallas,Tex., as described above.

[0993] An example of this is shown in FIG. 110. In this example, a tagor label printer 6200 is shown with an add-on Hyperlabel™ tag printershown at 6201. In use, an object 6202 to be printed, such as a productitem, packaging, or the like, is transferred through a printing regionon a conveyor 6203. In use, the printer 6200 will operate in the normalway to provide visible markings on the packaging, labelling or the like.The visible markings may correspond to product information, the name ofthe product, or the like, as well as identifiers such as bar codes.

[0994] The printer 6201 either before or after the visible markings areprovided, operates to print coded data as described above. The codeddata tags may be printed over an entire label or packaging, in whichcase the article is typically provided as a flat pack box oralternatively may be printed on one or more faces depending on therespective implementation.

[0995] In any event, in use the Hyperlabel™ tag printer 6201 generatesthe coded data such that it is indicative of a unique product itemidentifier such as an EPC. This can be achieved in a number of waysdepending the respective implementation as shown for example in FIGS.111, 112, 113.

[0996] In particular, in a first example shown in FIG. 111, the EPC isgenerated by an authority such as EPC Global (as described in 8.2.1).The EPC is provided to the manufacturing server 259, 20 typically aspart of a batch, and then allocated to the printer 6200 and the printer6201 as required. Thus, for example, the printer 6200 can generate a 2Dbar code representative of the EPC, which is printed in visible ink,with the Hyperlabel™ tag printer 6201 printing coded data which encodesthe EPC. The bar code would typically be generated in accordance with astandard symbology, as described above.

[0997] At some time during this process, the link between the EPC andits corresponding interface surface may be recorded at a product server251 as shown.

[0998] In a second example as shown in FIG. 112, the EPC is onlytransferred to the printer 6200, which prints the 2D bar code on theproduct item 6202. In this case, the netpage printer 6201 also includesa bar code reader 6203 which operates to read the two-dimensional 2D barcode and determine the EPC therefrom. The EPC is then used to generatethe coded data which is applied to the product item 6202, in the normalway. (Again an indication of the page interface description is providedto the product server 251.) It should also be noted that the netpageprinter 6201 and the product item 6202 may be separated in space andtime.

[0999] As a further alternative, the netpage printer 6201 can be adaptedto generate an EPC based for example on a predetermined manufacturernumber, assigned to the manufacturer, a product class number, and aserial number. In this case, having printed the Hyperlabel™ tags, anindication of the EPC is also transferred to the printer 6200 whichprints a 2D bar code on the box.

[1000] It will be appreciated that equivalent functionality can beprovided in conjunction with an RFID tag instead of a 2D bar code. Thusfor example, an RFID tag writing device, such as the Commander 320 13.56MHz RFID reader/writer, manufactured by Texas Instruments of Dallas,Tex., may be used to encode the EPC in an RFID tag which is thensubsequently read by the printing device to determine the EPC.

[1001] As a further alternative, it is possible to provide a printingdevice in the form of a printer 6201 which is also enabled to encode oneor more of RFID tags and 2D bar codes. It will be appreciated that inthe case of encoding 2D bar codes, the printer 6201 will also be adaptedto print visible markings as well as infrared markings and in particular2D bar codes. Similarly, the device may alternatively or additionally beprovided with a RFID tag writing device for encoding RF-ID tags.

[1002] 8.4 Hyperlabel™ Scanning

[1003] Item information typically flows to the product server inresponse to situated scan events, e.g. when an item is scanned intoinventory on delivery; when the item is placed on a retail shelf; andwhen the item is scanned at point of sale. Both fixed and hand-heldscanners may be used to sca Hyperlabel™ tagged product items, using bothlaser-based 2D scanning and 2D image-sensor-based scanning, usingsimilar or the same techniques as employed in the netpage pen.

[1004] As shown in FIG. 57, both a fixed scanner 254 and a hand-heldscanner 252 can communicate scan data to the product server 251. Theproduct server may in turn communicate product item event data to a peerproduct server (not shown), or to a product application server 250,which may implement sharing of data with related product servers. Forexample, stock movements within a retail store may be recorded locallyon the retail store's product server, but the manufacturer's productserver may be notified once a product item is sold.

[1005] 8.4.1 Hand Based Scanners

[1006] A number of designs of a hand based scanners Hyperlabel™ scanner252 will now be described Hyperlabel™ scanner.

[1007] 8.4.1.1 Hand-Held Hyperlabel™ Optical Reader

[1008]FIG. 58, FIG. 59, FIG. 60 and FIG. 61 show a first embodiment of aHyperlabel™ scanner 4000. The scanner is designed to image and decodeHyperlabel™ tags when its tip 4003 is brought into close proximity orcontact with a Hyperlabel™ tagged surface. The scanner can be operatedin free mode, in which it continuously and automatically scans tagswithin its field of view; or in triggered mode, in which it only scanstags when its trigger 4008 is held depressed. Although the scanner isdesigned with a limited depth of field, thus reducing the likelihood ofunintentional scans in free mode, triggered mode can be used to avoidunintentional scans. The trigger may also be configured to be manuallyoperated (as shown), or configured to be automatically activated whenthe scanner makes contact with the surface. Because an individualproduct item is tagged with a unique item ID, there is no possibility ofduplicate scans.

[1009] During normal operation the scanner returns the item ID encodedin a Hyperlabel™ tag, but ignores the position 86. The scannerdistinguishes between Hyperlabel™ tags, which encode item IDs, andgeneral netpage tags, which do not.

[1010] The scanner is a general-purpose Hyperlabel™ scanner suitable forshelf-stock scanning, point-of-sale scanning, and returns processing.Although not shown in the figures, the Hyperlabel™ scanner may usefullyincorporate a conventional laser-based bar code scanner for backwardscompatibility with linear bar codes. Alternatively or additionally, thescanner may be programmed to support scanning of extant linear and/ortwo-dimensional symbologies via its two-dimensional image sensor.

[1011] The scanner as shown is designed for tethered operation, whereinit obtains DC power from an external supply via a cable 2504, andtransmits decoded scan data to an external processor via the same cable2504. The scanner may be connected to a relay 253 which simply relaysthe scan data to a point-of-sale system or other processing system viawired or wireless communications, or the scanner may be directlyconnected to the processing system.

[1012] Alternative versions of the scanner incorporate a replaceable orrechargeable battery to allow untethered operation; a wirelesscommunication capability such as IrDA, Bluetooth, IEEE 802.15 (e.g.ZigBee) or IEEE 802.11 to allow untethered data transmission; and/orexternal contacts designed to mate with a tethered pod to allow in-podbattery charging and/or data transmission.

[1013] During a single period of proximity or contact with a taggedsurface, the scanner may successfully perform tens or even hundreds ofscans. Although even a single scan may be performed reliably based onbuilt-in error correction in the Hyperlabel™ tag, multiple scans can beused to further ensure reliability.

[1014] The scanner can indicate a correct (and possibly unique) scan byflashing its status LED 2426 and/or by producing an audible “beep”. Thebeep may be generated by the control unit to which the scanner isattached or by the scanner itself. It is useful if the status LED isflashed on a successful scan but the beep is only produced on a uniquescan (as identified by the control unit).

[1015] As shown in FIG. 58 through FIG. 62, the scanner consists of anose molding 4002 and two grip moldings 4004 and 4006. The grip moldingsmate together to hold the nose molding in place and to form the grip.Although shown with screw fasteners, the grip moldings may alternativelyincorporate snap fasteners. The nose molding incorporates an aperture,directly below the tip 4003, to accommodate the imaging field-of-viewcone 2100 and illumination field cones 2102. Further apertures in thegrip accommodate the status LED window 4010, the trigger 4008, and thecable 2504.

[1016] As shown in FIG. 59 and 62, the two near-infrared illuminationLEDs 2414 are disposed symmetrically about the imaging field-of-viewcone 2100 to provide a uniform illumination field across a range of tiltangles.

[1017] The optical assembly consists of a near-infrared filter 2104, anaperture disc 2106 incorporating a pin-hole aperture of between 0.5 mmand 1 mm in diameter, a focussing lens 2108, and a CMOS image sensor2412. To ensure accurate Hyperlabel™ tag acquisition across a range oftilt angles and relative scanner-to-Hyperlabel™ tag registrations, theimage sensor has a pixel array size of at least 128 by 128. The smallaperture and the large ratio of viewing distance to nominalfield-of-view diameter (i.e. in excess of 5:1) yields adequatedepth-of-field for reliable operation across a tilt range (i.e.combination of pitch and roll) of plus 45 degrees to minus 45 degrees,as well as contact-less tag acquisition. The optical magnification isdictated by the image sensor's pixel size and the required sampling rateof between 2:1 and 3:1 with respect to the worst-case (i.e.tilt-induced) pitch of the macrodots in the tag. The focussing lens ischosen to provide the required magnification while minimising overallspace requirements. The near-infrared filter 2104 may be of longpasstype or narrow bandpass type, depending on the required performance ofthe scanner with respect to ambient light levels, and thecharacteristics of the ink used to print the tags. If the scanner isrequired to perform in direct sunlight, then a narrow bandpass filter ispreferred. If the ink is narrowband, then a matching narrowband filteris also preferred.

[1018]FIG. 63 and FIG. 64 show close-up and exploded views of the opticsrespectively.

[1019] The image sensor is usefully of freeze-frame type rather thanrolling-shutter type to avoid skew between successive scan lines. Asuitable image sensor design is described in the present applicants'co-pending Australian Patent Application entitled “Methods and Systems(NPS041)” (docket number NPS041), filed 17 Feb. 2003. Suitablefreeze-frame image sensors are also available commercially from Micron,Texas Instruments and National Semiconductor.

[1020]FIG. 62 shows the image sensor 2412 attached via a flexible PCB2502 to the main PCB 2500. The main PCB as shown holds an imageprocessor 2410, controller 2400 and communications interface 2424. FIG.12 a corresponding block diagram of the electronics.

[1021] The image processor 2410 is closely coupled with the image sensor2412. A suitable design of the image processor is described theco-pending application (NPS041) identified above. As described in theco-pending application, the image sensor and image processor aredesigned to implemented together in the same chip, to minimiserequirements for high-speed external interfacing. The image processorsupports rapid readout of images from the image sensor into the imageprocessor's internal memory, followed by relatively slower readout fromthe image processor's internal memory to the external controller. Theimage processor also provides low-level image processing functions toassist the controller with image processing and further reduce the datarate to the controller. The image processor also controls the timing ofthe image sensor and the synchronisation of image acquisition with thestrobing of the illumination LEDs 2414.

[1022] In a typical configuration, image acquisition occurs at a rate ofbetween 50 and 150 frames per second. The exposure time of the imagesensor may be as low as 200 microseconds to allow accurate scanning evenduring significant relative motion between the scanner and the taggedsurface.

[1023] The image readout time of the image sensor is typically a coupleof milliseconds, which is only a fifth of the frame period at 100 framesper second. Thus the controller has ample time to process the acquiredimage in the image processor's internal memory. The image processor'smemory may be double-buffered to allow the controller to utilise thefull frame period for image processing.

[1024] As shown in FIG. 69, the image processor is designed to interfacewith the controller via a high-speed serial interface 2312. One exampleof such an interface is the high-speed synchronous serial interfaceprovided on Atmel controllers.

[1025] The controller 2400 includes a processor 2300 which runs softwareto perform a number of tasks. These tasks include overall control of thescanner; real-time decoding of images of Hyperlabel™ tags acquired andpre-processed by the image sensor 2412 and image processor 2410; andencoding and transmission of scan data to the external control unit viathe communications interface 2424 (or alternatively via the basebandcontroller 2416 and radio transceiver 2418). Image processing anddecoding are described in detail in the co-pending application (NPS041)identified above, as well as in the main body of this specification.

[1026] The controller incorporates a high-speed working memory 2302(such as a static RAM) for program data and for program code which isexecuting. It also incorporates a non-volatile program memory 2304 whichstores the program code, and which may be used to persistently (andhence securely) store scan data awaiting transmission. The controllermay incorporate a DMA controller 2306 for optimising the transfer ofdata between working memory and the high-speed serial interface. Thecontroller's components are interconnected via a shared control, addressand data bus 2308.

[1027] The processor senses depression of the scan switch 2428 via ageneral-purpose parallel input on the parallel interface 2312. Itcontrols the status LED(s) 2426 via outputs on the same parallelinterface. The controller 2400 may optionally include a programmablepulse width modulator (PWM) for driving the status LEDs.

[1028] When configured for wireless operation, the real-time clock 2420provides the basis for timestamping scan data when operating off-line.The power manager 2422 manages power utilisation and controls batterycharging. Both are controlled via the serial interface 2310.

[1029] The Hyperlabel™ scanner can be further augmented with amonochrome or color display to allow the operator to obtain productinformation based on scan data. This may include product-specificinformation such as descriptive information, and item-specificinformation such as manufacturing and use-by dates.

[1030] When the user of the scanner is a customer operating inself-checkout mode, the display can assist the customer in adding itemsto and removing items from their shopping cart. This may work inconjunction with a mode switch incorporated in the scanner which allowsthe customer to switch the scanner between the “add” mode and the“remove” mode prior to scanning an individual item. The mode can also besignalled more economically via one or more mode-indicating LEDs.

[1031] When operating in self-checkout mode, the customer may provide anidentity token, such as a magnetic stripe or smartcard-based paymentcard or RFID token, which allows the customer to be associated with thescanner for the duration of the shopping excursion. The reader for theidentity token may usefully be incorporated in the scanner. If theidentity token is a payment card, then payment can also be completedthrough the scanner.

[1032] 8.4.1.2 Handheld Hyperlabel™ Laser Scanner

[1033]FIGS. 72, 73 and 74 show a second embodiment of a Hyperlabel™scanner 4000.

[1034]FIGS. 72 and 73 use similar reference numerals to FIGS. 58 and 59to denote similar elements.

[1035] In this example, the optical assembly shown in FIG. 59 isreplaced with a laser based scanning system, an example of which isshown in FIG. 74.

[1036] As shown in FIG. 74, a scan beam 4540 is produced by a laser4502. The laser produces a narrowband near-infrared beam matched to thepeak wavelength of the near-infrared ink used to print the Hyperlabel™tags. An optional amplitude modulator 4503 allows the amplitude of thebeam to be modulated, e.g. for ambient light suppression or rangingpurposes as discussed below. An optional beam expander 4504 allows thebeam to be reduced to produce the desired spot size. The laser istypically a solid-state laser.

[1037] A pair of mirrors 4506 and 4507 injects the scan beam into linewith the retroreflective collection system, as described further below.

[1038] An optional focussing lens 4508 focusses the beam prior tosteering. A first deflector 4510 provides horizontal deflection of thebeam within a scan line of the patch. A second deflector 4511 providesvertical deflection of the beam between scan lines of the patch.

[1039] The maximum pixel sampling rate of the patch is usefully derivedfrom the maximum operating frequency of commercially-availablehorizontal deflectors. There are a number of available alternatives,including acousto-optic deflectors and resonant scanners. A practicalupper limit on the operating frequency of these devices is about 500KHz, and this is taken as the scan line rate for the purposes of thefollowing description.

[1040] Given a patch width of 150 pixels, the pixel rate of the scanneris therefore 75 MHz and the pixel time is 13 nanoseconds. The scan linetime is 2 microseconds, but to achieve line separation the actual scanline rate is 250 KHz rather than 500 KHz. The minimum patch time istherefore 600 microseconds and the maximum patch rate is 1.6 KHz.

[1041] The vertical deflector 4511 is only required to operate at themaximum patch rate of 1.6 KHz. Again there are a number of availablealternatives, including acousto-optic deflectors, resonant scanners,rotating polygon mirrors, galvanometers and piezoelectrically-actuatedplatforms.

[1042] The two deflectors 4510 and 4511 are driven by synchroniseddrivers 4512 and 4513 respectively, each incorporating scan generation,amplification etc.

[1043] The angle of the output beam of the horizontal and verticaldeflectors 4510 and 4511 is transformed into a spatial offset within thepatch by an angle-to-displacement transform lens 4516. This has thebenefit that the bundle of (time-displaced) scan beams which make up thepatch beam is collimated, thus the sampling frequency of the patch isunaffected by distance to the tagged surface.

[1044] The patch beam is focussed and its focal plane is flattened by afocussing and field-flattening lens 4526.

[1045] During the “exposure” time of a single pixel the scan beam spoteffectively rests at a single point on the product item 201.

[1046] As shown in FIG. 75, the scanner's light collection system isretroreflective, significantly increasing the scanner's signal-to-noiseratio. As shown in the figure, divergent rays 4546 and 4548, diffuselyreflected where the scan beam strikes the surface of the tagged productitem, converge through the transform lens 4516, follow the reverse pathof the scan beam through the deflectors 4511 and 4510 to emerge centeredon the scan beam, are largely unaffected by the focussing lens 4508,largely bypass the mirror 4507, and are finally focussed by a collectinglens 4530 onto a photodetector 4536. An optional near-infrared filter4532 further helps reject of ambient light. The photodetector is of anysuitable type, such as a solid-state photodiode or a photomultipliertube.

[1047] The signal from the photodetector 4536 is amplified by amplifier4536 and is converted to a digital value by analog-to-digital converter(ADC) 4538. The ADC operates at the scanner's pixel rate, i.e. 100 MHz.The ADC is synchronised with the horizontal deflector driver 4512.

[1048] In use, the photodetector circuit can be modulated in accordancewith the modulation of the laser, as achieved by the amplitude modulator4503, to thereby assist with the suppression of ambient light.

[1049] In particular, during an integration (or “exposure”) period, thephotodetector 4536 produces a photocurrent which is proportional to theintensity of light incident upon the photodetector. When the controlledlight source, in this case, the scanning beam 4540 is off, the lightincident upon the photodetector will primarily be ambient light. Whenthe scanning beam is on, the light incident upon the photodetector 4536will be formed from light reflected from the product item, and theambient light.

[1050] Accordingly, the photodectector system can be adapted to operatein two phases in accordance with the modulation of the scanning beam4540. During a first phase, when the scanning beam 4540 is off, thephotodetector circuit is adapted to detect the incident light and fromthis determine and effectively memorise the ambient light level.

[1051] In the second phase when the scanning beam is activated, thephotocurrent in the photodetector 4536 increases in proportion to thelight incident thereon, based on the reflected radiation and the ambientlight. This “total light signal” is corrected by effectively subtractingthe memorised ambient light level signal, to generate a “differencesignal”, which is indicative of the reflected scanning beam only. Thisallows the effects of ambient light to be reduced.

[1052] This process and a photodetector circuit suitable for performingsuch operation are described in the co-pending PCT Publication No. WO03/044814 entitled “Active Pixel Sensor” filed 22 Nov. 2002, thecontents of which are incorporated herein by cross-reference.

[1053] The electronics of the scanner will be similar to those of FIG.69.

[1054] 8.4.1.3 Hyperlabel™ Pen

[1055]FIG. 65, FIG. 66 and FIG. 69 show a preferred embodiment of aHyperlabel™ pen 3000. The pen is designed to image and decodeHyperlabel™ tags when its nib 3006 is brought into close proximity orcontact with a Hyperlabel™ tagged surface. The pen can be operated in“hover” mode, in which it continuously and automatically scans tagswithin its field of view; or in contact mode, in which it only scanstags after a “pen down” event, i.e. when its nib switch 2428 is engagedand/or its nib force sensor 2430 registers a threshold force. Hover modeis useful when the pen is used to drive a cursor on a display screen. Itis less useful when interaction is exclusively paper-based.

[1056] During normal operation the pen decodes a succession of tagpositions 86, refines these positions according to the position andorientation of each tag within the field of view, and thereby generatesa succession of nib positions representative of the pen's motion withrespect to the tagged surface. As shown in FIG. 33 the pen thusgenerates a succession of strokes referred to collectively as digitalink, each stroke delimited by a pen down and a pen up event. Each strokeidentifies the IDs of the one or more pages or regions within which thestroke was captured.

[1057] The pen incorporates a marking nib and ink cartridge 3006,allowing the user to write on a tagged page while simultaneouslygenerating digital ink. The cartridge is replaceable, and a non-marking“stylus” cartridge may be substituted for non-marking operation.

[1058] The pen as shown is designed for tethered operation, wherein itobtains DC power from an external supply via a cable 2504, and transmitsdigital ink to an external processor via the same cable 2504. The penmay be connected to a relay device 44 which simply relays the digitalink to a remote processing system (e.g. page server) via wired orwireless communications, or the pen may be directly connected to theprocessing system.

[1059] Alternative versions of the pen incorporate a replaceable orrechargeable battery to allow untethered operation; a wirelesscommunication capability such as IrDA, Bluetooth, IEEE 802.15 (e.g.ZigBee) or IEEE 802.11 to allow untethered data transmission; and/orexternal contacts designed to mate with a tethered pod to allow in-podbattery charging and/or data transmission.

[1060] As shown in FIG. 65 through FIG. 67, the pen consists of a basemolding 3002 and a cover molding 3004. The moldings mate together toform the pen body. Although shown with screw fasteners, the moldings mayalternatively incorporate snap fasteners. The base molding incorporatesan aperture, directly above the nib 3006, to accommodate the imagingfield-of-view cone 2100 and illumination field cones 2102. Furtherapertures in the body accommodate the status LED window 3014, resetswitch 3016, and the cable 2504.

[1061] The Hyperlabel™ pen 3000 and the hand-held Hyperlabel™ scanner4000 are designed to share the same optics and electronics. Thefollowing description therefore focusses on those areas where the pendiffers from the scanner.

[1062] As shown in FIG. 66, the pen incorporates a force sensor 2430coupled to the ink cartridge 3006. A housing 3008 contains a pliablesleeve 3010 designed to grip the removable cartridge 3006 and pushagainst an element 3012 which couples it with the force sensor 2430. Theforce sensor may usefully be of resistive, piezo-resistive, orpiezo-capacitive type.

[1063]FIG. 68 shows the optics and PCB in a linear arrangement suited tothe pen, in contrast with the folded arrangement suited to the scanner,as shown in FIG. 5.

[1064] As shown in the block diagram of the electronics illustrated inFIG. 12, the controller's ADC 2314 converts the analog signal from thepen's nib-coupled force sensor 2430. The pen optionally incorporates anib switch 2428, placed in line with the force sensor 2430 to provide apower-efficient and reliable pen-down signal, as well as a basis forforce sensor offset calibration. The force signal is included in thedigital ink generated by the pen. It may be used in variousapplication-specific ways, including to modulate the thickness ofstrokes rendered to match the physical strokes produced by the markingnib.

[1065] It will be appreciated that the pen 3000 described above is analternative embodiment of the netpage pen 101. The pen 3000 and netpagepen 101 may be used interchangably, and will therefore be referred togenerally as netpage pens.

[1066] 8.4.1.4 Glove Scanner

[1067]FIG. 70 shows a preferred embodiment of a “glove” Hyperlabel™scanner 5000. The glove scanner is designed to image and decodeHyperlabel™ tags when its “thimble” imaging unit 5008 is brought intoclose proximity or contact with a Hyperlabel™ tagged surface. Thescanner can be operated in free mode, in which it continuously andautomatically scans tags within its field of view; or in triggered mode,in which it only scans tags when its trigger is held depressed. Althoughthe scanner is designed with a very limited depth of field, thusreducing the likelihood of unintentional scans in free mode, triggeredmode can be used to avoid unintentional scans. Because an individualproduct item is tagged with a unique item ID, there is no possibility ofduplicate scans.

[1068] The glove scanner is a general-purpose Hyperlabel™ scannerparticularly suited to automatic scanning of stock during handling, suchas during shelf replenishment. Unlike other glove-mounted bar codescanners which image in a direction parallel to the outstretched finger,the Hyperlabel™ glove scanner images in a direction normal to theunderside of the grasping finger. This mode of operation is madepossible by the smallness of the field of view required to acquire aHyperlabel™ tag, i.e. of the order of 5 mm.

[1069] In the glove scanner 5000, the viewing distance is shortenedrelative to the viewing distance in the hand-held scanner 4000 andnetpage pen 3000. This allows the imaging unit 5008 to be compact, butreduces the depth of field. This is not a problem, however, since theimaging unit is designed to be used when close to and parallel to atagged surface.

[1070] The imaging unit 5008 contains the same optical components as thehand-held scanner, including the near-infrared illumination LEDs 2414.In addition, it incorporates a 30-60-90 prism 5012 which folds theimaging cone (to line it up with the image sensor mounted almostnormally to the surface 5014) and increases the viewing distance. Sincethe thimble is less susceptible to ambient light than the hand-heldscanner, the near-infrared filter 2104 is optional.

[1071] The imaging unit also incorporates the trigger switch (not shown)which registers contact with a tagged surface. Alternatively oradditionally, the trigger switch may be placed between thumb andforefinger for manual activation.

[1072] The imaging unit incorporates both the image sensor 2412 and theimage processor 2410, which are usefully combined into a single compactchip as described in the co-pending U.S. application U.S. Ser. No.______ entitled “Image Sensor with Digital Framestore” (docket no.NPS047-US-NPS054) filed 17 Feb. 2004.

[1073] The imaging unit 5008 is connected to the processing unit 5006via a power and high-speed data cable 5010. The remainder of the scannerelectronics are incorporated in the processing unit, including theprocessor 2400 and communications interface 2424. The processing unit isconnected to an external control unit via a power and data cable 2504 inthe usual way.

[1074] Both the imaging unit 5008 and the processing unit 5006 areattached to a harness 5004, constructed from elastic material, which isworn like a glove.

[1075] 8.4.2.1 Fixed Hyperlabel™ Laser Scanner

[1076] A first example of a design of a fixed Hyperlabel™ laser scanner254 will now be described.

[1077]FIG. 76 shows the central unit 1501 of a preferred embodiment of afixed Hyperlabel™ laser scanner 1500 suitable for incorporation in aretail checkout 1000.

[1078] To accommodate as large a proportion as possible of the fullrange of product items which may need to be scanned, the Hyperlabel™scanner 1500 is designed to accurately scan any item which fits on the500 mm wide conveyor 1014 of the checkout 1000. It is configured toautomatically scan a single item at a time as it passes by on theconveyor at a speed of up to 500 mm/s. It may scan three sides and thetops of items from both sides of the conveyor, up to an item height of500 mm, thus providing a five-sided scanning function.

[1079] The scanner is typically able to scan product items rangingacross the full size range, e.g. ranging from packets of corn flakes topackets of chewing gum, as well as partially labelled items such asglass bottles, jars and shrink-wrapped produce.

[1080] If the scanner acquires two different item IDs simultaneouslythen it flags an error to the operator and stops the conveyor, therebypreventing accidental or deliberate (and therefore fraudulent) occlusionof an item by other items. The operator must then move the offendingitems to the input side of the conveyor and restart the conveyor.

[1081] The uniqueness of the item ID prevents any item from beingrecorded as a sale more than once.

[1082] The scanner detects the transit of an object on the conveyor. Ifit detects the transit of an object which fails to scan, then it flagsan error and stops the conveyor. The operator may then move theoffending item to the input side of the conveyor and restart theconveyor, or scan the item manually, e.g. using the hand-heldHyperlabel™ scanner 4000.

[1083] Hyperlabel™ tagging covers a large proportion of the surface of aproduct item. The basic Hyperlabel™ scanning strategy therefore consistsof sparsely sampling the scan volume. This basic strategy may then berefined to improve scan accuracy and/or scan efficiency.

[1084] The acquisition of a two-dimensional Hyperlabel™ tag requires thescanning of a spatially coherent two-dimensional “patch” large enough tobe guaranteed to contain at least one entire tag. This contrasts withthe acquisition of a one-dimensional bar code, which only requires thescanning of a spatially coherent line. There is therefore a fundamentalrequirement to provide two levels of beam steering, where the firstlevel provides the two-dimensional scan of the beam within a patch, andthe second level provides the two- or three-dimensional scan of thepatch within the scan volume. For the purposes of the followingdiscussion the second level of beam steering is taken to apply to a“patch beam”.

[1085] As described earlier in this specification, a Hyperlabel™ tag hasa maximum feature period of about 150 microns. Assuming a sampling rateof two and a minimum inclination between a tagged surface and the scanbeam of 45 degrees, a sampling spot period of 50 microns and a samplingspot size of between 50 and 100 microns is required, depending on beamcross-section. At a sampling rate of two, the required circular field ofview has an image-space diameter of about 150 pixels. This in turndetermines the dimensions of the patch, i.e. 150 by 150 pixels.

[1086] As shown in FIG. 76, a scan beam 1540 is produced by a laser1502. The laser produces a narrowband near-infrared beam matched to thepeak wavelength of the near-infrared ink used to print the Hyperlabel™tags. An optional amplitude modulator 1503 allows the amplitude of thebeam to be modulated, e.g. for ranging purposes as discussed below. Anoptional beam expander 1504 allows the beam to be reduced to produce thedesired spot size. The laser may be a solid-state or gas laser such asHeNe laser.

[1087] A pair of mirrors 1506 and 1507 injects the scan beam into linewith the retroreflective collection system, as described further below.

[1088] An optional focussing lens 1508 focusses the beam prior tosteering. A first deflector provides horizontal deflection of the beamwithin a scan line of the patch. A second deflector 1511 providesvertical deflection of the beam between scan lines of the patch.

[1089] The maximum pixel sampling rate of the patch is usefully derivedfrom the maximum operating frequency of commercially-availablehorizontal deflectors. There are a number of available alternatives,including acousto-optic deflectors, resonant scanners and rotatingpolygon mirrors. A practical upper limit on the operating frequency ofthese devices is about 500 KHz, and this is taken as the scan line ratefor the purposes of the following description.

[1090] Given a patch width of 150 pixels, the pixel rate of the scanneris therefore 75 MHz and the pixel time is 13 nanoseconds. The scan linetime is 2 microseconds, but to achieve line separation the actual scanline rate is 250 KHz rather than 500 KHz. The minimum patch time istherefore 600 microseconds and the maximum patch rate is 1.6 KHz.

[1091] The vertical deflector 1511 is only required to operate at themaximum patch rate of 1.6 KHz. Again there are a number of availablealternatives, including acousto-optic deflectors, resonant scanners,rotating polygon mirrors, galvanometers and piezoelectrically-actuatedplatforms.

[1092] The two deflectors 1510 and 1511 are driven by synchroniseddrivers 1512 and 1513 respectively, each incorporating scan generation,amplification etc.

[1093] The angle of the output beam of the horizontal and verticaldeflectors 1510 and 1511 is transformed into a spatial offset within thepatch by an angle-to-displacement transform lens 1516. This has thebenefit that the bundle of (time-displaced) scan beams which make up thepatch beam is collimated, thus the sampling frequency of the patch isunaffected by distance to the tagged surface.

[1094] The patch beam is steered by a mirror 1520 attached to apiezoelectric tip-tilt platform 1518. Fine steering control within thescan volume is achieved by steering the patch beam within the confinesof a scan mirror 1528, as illustrated in FIG. 77, FIG. 78 and FIG. 79.Gross steering control within the scan volume is achieved by steeringthe patch beam between different scan mirrors 1528 a, 1528 b etc., asillustrated in FIG. 80, FIG. 82 and FIG. 84. Although FIG. 82 shows fourscan mirrors 1528 a, 1528 b etc. arranged vertically, and FIG. 84 showsthree scan mirrors 1528 a, 1528 e and 1528 f arranged horizontally,there are in practice any number of scan mirrors distributed bothvertically and horizontally within the scan posts to effectomnidirectional scanning.

[1095] A typical tip-tilt platform has a resonant frequency of about 1KHz, i.e. an access time of about 1 millisecond. This results in aneffective patch rate of about 600 Hz. Faster beam-steering solutions,such as acousto-optic deflectors, may be used to achieve patch beamsteering at the maximum patch rate.

[1096] As shown in FIG. 84, scan mirrors 1528 e and 1528 f, located atthe sides of the scan posts 1022 and facing diagonally across the scanvolume between the scan posts, provide support for scanning the leadingand trailing side of a product item, i.e. just after the item enters thescan volume and just before the item leaves the scan volumerespectively.

[1097] The focus of the beam can be dynamically adjusted for the pathlength associated with the selected scan mirror. The focus of the beamcan be altered by translating a lens element, e.g. within the beamexpander 1504, using a precision piezoelectric translation stage.

[1098] Depending on the characteristics of the beam produced by thelaser 1502, and on the required spot size, the depth of field of thescan beam can be increased by dividing the scan volume into two or moredepth zones and individually scanning patches in all zones withzone-specific beam focus.

[1099] The deflector drivers 1512 and 1513 may modulate the pixel andline scan rate to accommodate patch distortion caused by the state ofthe tip-tilt platform 1518.

[1100] The patch beam is focussed and its focal plane is flattened by afocussing and field-flattening lens 1526.

[1101] During the “exposure” time of a single pixel the scan beam spoteffectively rests at a single point on the product item 201. The speedof the conveyor induces a negligible skew. Even during the300-microsecond scan time of the entire patch, the object moves onlyabout 150 microns, i.e. about 3% of the patch size.

[1102] Although conveyor motion with respect to patch size is nominallyminimal, the motion may be irregular due to the imprecise nature of thecoupling between the motor and the conveyor. The scanner may thereforeinclude a motion sensor 1556 which senses the actual motion of theconveyor, and may use the resultant known motion of the conveyor tocorrect any motion-induced distortions in the sampled patch, such asinter-line skew.

[1103] As shown in FIG. 81, the scanner's light collection system isretroreflective, significantly increasing the scanner's signal-to-noiseratio. As shown in the figure, divergent rays 1546 and 1548, diffuselyreflected where the scan beam strikes the surface of the tagged productitem, converge through the transform lens 1516, follow the reverse pathof the scan beam through the deflectors 1511 and 1510 to emerge centeredon the scan beam, are largely unaffected by the focussing lens 1508,largely bypass the mirror 1507, and are finally focussed by a collectinglens 1530 onto a photodetector 1536. An optional near-infrared filter1532 further helps reject of ambient light. The photodetector is of anysuitable type, such as a solid-state photodiode or a photomultipliertube.

[1104] The signal from the photodetector is amplified by amplifier 1536and is converted to a digital value by analog-to-digital converter (ADC)1538. The ADC operates at the scanner's pixel rate, i.e. 100 MHz. TheADC is synchronised with the horizontal deflector driver 1512.

[1105]FIG. 85 shows a block diagram of the electronics of the scanner,including an integrated scanner controller 1600. Where reference numbersin FIG. 85 match those described in FIG. 69, they refer to the same orsimilar components and functions.

[1106] The fixed Hyperlabel™ scanner 1500 utilises the same imageprocessor 2410 as the hand-held Hyperlabel™ scanner, and netpage pensdescribed in FIGS. 8, 9, 65 and 58, here configured to directly capturethe digital output of the ADC 1538. The controller 1600 is ahigher-performance but otherwise similar controller to the controllerdescribed in FIG. 69. It decodes Hyperlabel™ tags in real time andcommunicates the resultant scan data over the communications interface2424 to the control unit or retail processing system to which thescanner is attached. It controls the conveyor motor 1560 via theconveyor motor driver 1558. It controls the scanning operation via thehorizontal and vertical deflector drivers 1512 and 1513, and thetip-tilt patch beam steering driver 1522. During range finding itcontrols the amplitude of the laser beam via the amplitude modulator1503.

[1107] As an alternative to the retroreflective collection system, or inaddition to it, one or more photodetectors with collection lenses andnear-infrared filters may be placed closer to the scan volume, i.e.within the scan posts 1022.

[1108] As shown in FIG. 82 and FIG. 83, the scanner's central unit 1501is designed to be housed below the conveyor 1014, and to betime-multiplexed between the two scan posts 1022. An additional tip-tiltmirror 1550 is used to direct the scan beam to mirror 1552 associatedwith one or other scan post, and thence to mirror 1554 which directs thebeam up the corresponding scan post 1022 to mirrors 1528 a etc. toeffect the omnidirectional scan.

[1109] Rather than time-multiplexing a single scanner unit 1501, it isalso possible to use two separate scanner units.

[1110] The scanner can be operated as a range finder by modulating apulse onto the scan beam 1540, using the amplitude modulator 1503, andprecisely measuring the nanosecond-scale time-of-flight of the pulse tothe photodetector 1534.

[1111] Range finding can be used for two distinct purposes. It can beused to detect the presence or absence of an object in the scan volume,and it can be used to determine the distance to the object surface, i.e.the depth of the object surface with respect to the scanner. The knowndepth of object surface being scanned can be used on a per-patch basisto optimise the focus of the beam and hence the scan spot size.

[1112] The scanner may also employ adaptive focus. If it succeeds inacquiring tag targets within a particular patch, but fails tosuccessfully acquire and decode the tag data, then it may rescan thepatch with a different beam focus.

[1113] The scanner may usefully operate in three modes. In the first“detection” mode the scan volume is nominally empty and the scanner isattempting to detect an object on the input edge of the scan volume,either using range finding or using a separate object detector based onone or more light sources and photodetectors.

[1114] In the second “profiling” mode the scan volume contains adetected object and the scanner is determining the two- orthree-dimensional profile of the object from the point of view of thescanner, using rapid range finding throughout the scan volume.

[1115] In the third “scanning” mode the scan volume contains a profiledobject and the scanner is actively scanning the object as describedpreviously. Given a known object profile the scanner can optimise thepatch distribution to evenly cover the object and maximise the chancesof tag acquisition.

[1116] It is also possible to operate the scanner with a fixed patchscan pattern rather than a scan pattern adapted to the profile of theobject. In this case the tip-tilt steering mirror 1520 may be replacedby a rotating holographic disc, each of whose segments encodes adifferent beam direction (and possibly beam focus). In this way the beamcan be steered at in an arbitrary pre-determined pattern at the maximumpatch rate. A scanner which utilises a holographic disc is described inDickson, L. D. and G. T. Sincerbox, “Optics and holography in the IBMsupermarket scanner”, in Selected Papers on Laser Scanning andRecording, SPIE Volume 378, referenced below.

[1117] The maximum patch rate of the scanner means that it can denselyscan the 500 mm height and 500 mm depth of the scan volume at about 8 Hz(or at half this rate if time-multiplexed between the two sides of theconveyor). At a conveyor speed of 500 mm/s, the scanner is able toperform 5 such scans during 300 mm of product item movement. Thisprovides coverage of the three sides and top of the product itemrequired to be scanned by the scanner from one side of the conveyor.

[1118] If a fixed scan pattern is used then the scanner has no profilingmode.

[1119] Although this description has assumed a pixel rate of 100 MHz,the scanner can be configured to operate at a lower rate. In this casethe patch size is widened to accommodate increased skew induced byconveyor motion. Alternatively, the maximum speed of the conveyor may bereduced.

[1120] A number of components, systems and techniques related to thepresent invention are described in Beiser, L. and B. J. Thompson (eds.),Selected Papers on Laser Scanning and Recording, SPIE Volume 378 (SPIE1985), and in Smith, W. J., Modern Optical Engineering, 3rd edition(McGraw-Hill 2000), the contents of both of which are hereinincorporated by cross-reference.

[1121]8.4.2.2 Fixed Hologram Controlled Hyperlabel™ Laser Scanner

[1122] As an alternative to using the mirror based system to control thescanning beam, a holographic optical element may instead be used. Anexample of this will now be described with reference to FIG. 86.

[1123] In this example, a rotating holographic optical element 4600 isdesigned to both generate a scanning beam which moves over a patch, andto position the patch on the product item 201. This therefore removesthe requirement for both the horizontal and vertical deflectors 1510 and1511, and the mirror based control system 1518, 1528, as shown.

[1124] The functioning of the device otherwise is substantially asdescribed above with respect to the mirror based control system and willnot therefore be described in any further detail.

[1125] However, it will be appreciated by persons skilled in the artthat the holographic element may direct the patch beam onto a number ofmirrors equivalent to the mirrors 1528, to allow for appropriatedirecting of the scanning beam onto the product item 201, as shown inFIG. 87.

[1126] Alternatively, the beam may be aimed directly into the sensingregion. In this latter case, it will be appreciate that the patch beamwill enter the sensing region from substantially one direction. However,this still allows retail checkouts to be achieved as will be describedin more detail below.

[1127] 8.4.3.1 Column Array Based Retail Checkout

[1128]FIG. 88, FIG. 89, FIG. 90 and FIG. 91 show a first example of aretail checkout 1000 which incorporates and is adapted to exploit thefixed Hyperlabel™ laser scanner 1500. This may be either the mirrorbased or hologram based laser scanner systems, as will be appreciated bypersons skilled in the art.

[1129] The checkout is designed to semi-automatically scan grocery andother items conveyed past the Hyperlabel™ scan posts 1022. The customertransfers items from a shopping cart 1004 to the conveyor 1014. Thecheckout operator 1002 ensures that tagged product items 1034 proceedthrough the scanner singly, but otherwise allows scanning to proceedautomatically. Unique item IDs make semi-automatic scanning possible,and semi-automatic scanning of unique IDs result in more accuratescanning and prevents fraudulent collusion between the operator and thecustomer.

[1130] The operator diverts untagged items such as fruit and vegetablesto a set of scales 1028 for manual entry via the register touchscreen1026.

[1131] Tagged items slide off the conveyor into an output holding area1042 after being scanned.

[1132] Manually-processed untagged items are pushed by the operator intothe holding area. The holding area includes a moveable boom 1030 whichallows the holding area to simultaneously receive items for one customerwhile holding items for the previous customer. This allows the previouscustomer to continue bagging items in the bagging area 1036 while thenext customer is being serviced, thus optimising checkout throughput.

[1133] The checkout includes a register display 1008 visible to thecustomer. This displays the description and price of the most recentlyscanned or manually entered item, as well as the running total. Anindicator post 1012 incorporated in the checkout advertises thecheckout's number, availability and other status information.

[1134] A hand-held Hyperlabel™ scanner 4000 allows the operator tomanually scan bulky items or items which otherwise fail to scanautomatically.

[1135] The checkout also includes a cash drawer 1006, EFTPOS terminal1018, transaction counter 1020, and receipt printer 1010. The receiptprinter may be a netpage printer, as described in the main part of thisspecification, thus providing the customer with the downstream benefitsof netpage interactivity, such as the ability to record receipted itemsin a personal inventory, update a transaction history, and obtainproduct-level and item-level information about receipted items.

[1136] The receipt may also be printed on the reverse side withnetpage-interactive advertising, special offers, and redeemable coupons.

[1137] To support interoperability with bar coded as well as RFID taggeditems, the checkout may incorporate a traditional bar code readingcapability as well as an RFID tag reading ability.

[1138] Both the fixed Hyperlabel™ laser scanner 1500 and the hand-heldHyperlabel™ scanner 4000 can provide scan data in a standard format andaccording to standard interfaces and protocols, and can thus beessentially plug-compatible with other item ID (e.g. EPC) scanners suchas RFID readers, as described for example in U.S. Pat. No. 5,280,159, ora bar code scanner, examples of which are described in U.S. Pat. No.5,340,973, or U.S. Pat. No. 5,126,544.

[1139] 8.4.3.2 Transparent Conveyor Based Retail Checkout

[1140] In an alternative configuration, the laser based scanning systemis provided within the checkout to direct the scanning beam into thesensing region through the conveyor.

[1141] In this example, shown in FIG. 92, the central unit 1501 of thescanning device is positioned below the conveyor to allow the scanningbeam to pass through the conveyor into the sensing region. Similarreference numerals to FIGS. 88 and 89 denote similar elements, and willnot therefore be described in detail.

[1142] In this example, the conveyor belt 1014 is made at leastpartially invisible to infrared radiation. This is preferably achievedby providing holes in the conveyor belt which are of a sufficient areato allow the scanning beam to illuminate the product item and for thereflected radiation to pass back through the hole and be detected by thecentral unit 1501, as shown in FIG. 92.

[1143] This may be achieved by having the entire conveyor belt, or aportion 1014 a thereof contructed from a mesh which has sufficientapertures for the laser scanning beam to pass therethrough.

[1144] Alternatively, this may be achieved by utilising aninfrared-transparent conveyor belt which is infrared-transparent almostover the entire surface or at least a portion thereof. For example, ainfrared-transparent strip 1014 a could be provided along the centre ofthe conveyor belt as shown.

[1145] Operation is then substantially as described above.

[1146] It will be appreciated that this could be utilised in addition tothe column based checkout system described above to thereby furtherenhance the chance of product items scanning correctly regardless oftheir orientation on the conveyor belt.

[1147] 8.4.4 Other Scanner Configurations

[1148] The Hyperlabel™ laser scanner 1500 may usefully be incorporatedin other checkout devices.

[1149] A variant of the Hyperlabel™ laser scanner may be incorporated ina self-checkout where the customer is responsible for scanning items.Even if the customer is still required to manually present items to thescanner, the unique item ID ensures that duplicate scans do not occur,and Hyperlabel™ tagging ensures that the customer is more easily able toscan items without having to be concerned with correctly presenting abar code.

[1150] A variant of the Hyperlabel™ scanner may also be incorporated ina shopping cart in such a way that items added to the cart areautomatically scanned and added to a record of the cart's content, anditems removed from the cart are automatically scanned and removed fromthe record of the cart's content. In the shopping cart the scanner isconfigured to densely scan two scan volumes, each of which covers theentire opening into the cart. One scan volume lies above the other, andthe scanner is configured to distinguish an item addition from an itemremoval based on the order in which the item's ID is scanned in the twoscan volumes. Beam coverage of the scan volumes is assisted by mirrorsmounted around the opening into the cart.

[1151] It is also possible to provide a scanner which is adapted to scanboth Hyperlabel™ tags and 2D bar codes or RFID tags.

[1152] In the first instance, the scanning optics for sensing coded dataand bar codes may be substantially identical. Accordingly, the scanningdevice may be similar to those shown in FIG. 81. In many cases, nomodification of the scanning device is required. In some instanceshowever it is necessary to provide an alternative light source such as alaser which generates visible light to allow the 2D bar code to bedetected. An example of this is shown in FIG. 615.

[1153] Similarly, it is also possible for the scanning device toincorporate an RF-ID tag reader. Again, this will be a standard RFID tagreader which is adapted to decode the EPC stored in the RFID tag.

[1154] 8.5 Hyperlabel™-Based Netpage Interactions

[1155] A product item whose labelling, packaging or actual surface hasbeen Hyperlabel™ tagged provides the same level of interactivity as anyother netpage.

[1156] There is a strong case to be made for netpage-compatible producttagging netpage turns any printed surface into a finely differentiatedgraphical user interface akin to a Web page, and there are manyapplications which map nicely onto the surface of a product. Theseapplications include obtaining product information of various kinds(nutritional information; cooking instructions; recipes; relatedproducts; use-by dates; servicing instructions; recall notices); playinggames; entering competitions; managing ownership (registration; query,such as in the case of stolen goods; transfer); providing productfeedback; messaging; and indirect device control. If, on the other hand,the product tagging is undifferentiated, such as in the case of anundifferentiated 2D bar code or RFID-carried item ID, then the burden ofinformation navigation is transferred to the information deliverydevice, which may significantly increase the complexity of the userexperience or the required sophistication of the delivery device userinterface.

[1157] 8.5.1 Product Registration

[1158] A Hyperlabel™ tagged product can contain a <register> buttonwhich, when activated with a netpage pen, registers the netpage user asthe owner of the product. The user's contact information, which isalready recorded on the netpage system, can be automatically transmittedto the product manufacturer who can record it in their customerdatabase. The registration process can automatically add themanufacturer to the user's e-mail contact list, thus allowing themanufacturer to send the user e-mail relevant to the product, such asrelated special offers, recall notices, etc. If the manufacturer abusestheir e-mail privileges, the user can bar them in the usual way.

[1159] An example of the procedure for implementing this will bedescribed with reference to FIG. 101 which shows a system for allowingproduct registration. In particular, in this example, the user utilisesa netpage pen 101, or other suitable sensing device, such as one of thescanning devices described above, to select the <register> button on theproduct item 201.

[1160] The netpage pen 101 captures an item ID and digital inkrepresenting a click, from the product interface surface, and forwardsthis to the netpage pen server 500 associated with the netpage pen. Thepen server 500 uses a name server 501 to resolve the item ID to aproduct server address, for example by using the manufacturer number, asdescribed above.

[1161] The pen server 500 uses the server address to contact the productserver 251 and obtain the interface surface description therefrom. Aspreviously described, the interface surface description defines theaction associated with respective positions or on the interface surface,and accordingly, the pen server 500 interprets the pen input in relationto the interface description and as a result generates a registrationrequest. The request transferred to a manufacturer server 502, typicallyin accordance with a manufacturer server address determined from theitem ID. The manufacturer server 502 is operated by the manufacturer ofthe product item, or an entity associated with the manufacturer whichoperates to provide product registration facilities.

[1162] The manufacturer server 502 is responsive to the registrationrequest to register the user of the netpage pen 101 as the owner of theproduct item 201. This will be achieved by having the manufacturerserver 502 update a database which contains information indicative ofthe current owner of the product item. It will therefore be appreciatedthat this is generally updated with information such as the user'scontact information. In one example, this is achieved by having the penserver provide an indication of user details previously associated withthe netpage pen 101, as part of the registration request.

[1163] Once registration has been performed, an optional response can besent by the manufacturer server 502 confirming that registration iscomplete. This may be provided to the user via a terminal 504, such asthe netpage printer, or by any other suitable indicating device.

[1164] Accordingly, the selection of an appropriate <register> button,which is typically formed from a respective region on the product item'sinterface surface, allows the user the register themselves with themanufacturer as the existing owner of the product item.

[1165] It will be appreciated that the registration system may include anumber of variations. For example, in the above described example, theuser details are automatically provided as part of the registrationrequest. However, alternatively the user details may be provided in asubsequent step, as shown in FIG. 102.

[1166] In particular, in this example, the manufacturer server 502responds to the registration request to generate a user details requestform, which is transferred to a terminal, which may be any form ofterminal that allows completion of the form by the user.

[1167] In one example, the terminal is formed from a netpage printer601, which presents the user with an interactive form which can becompleted using the netpage pen 101 in accordance with techniquesdescribed above with respect to netpage interaction.

[1168] Thus, the form will include a number of fields into which theuser can enter information using the netpage pen 101. The netpage pentransmits digital ink representative of the completed form information,to the pen server 500. The pen server 500 (or page server 10) retrievesa form description using the form page ID or region ID using the itemID, digital ink and interface description, and uses this to interpretthe digital ink to generate data representing the user details. The userdetails are then provided to the manufacturer server 502, which operatesto register the user, and optionally provide a registration response asdescribed above.

[1169] As a further alternative, the user may be identified to themanufacturer through the use of an alias ID, as previously described.

[1170] As an alternative to providing a <register> button on the productitem interface surface, the sensing device can be adapted to operate ina mode, such as a <register> mode, which allows registration to betriggered by clicking anywhere on the interface surface. In this case,the sensing device need only capture the item ID, with the pen serverbeing responsive to this to generate the registration request.

[1171] Selection of an appropriate mode may be achieved using an inputprovided on the sensing device, or alternatively, by the use of asuitably encoded netpage which has buttons provided thereon.

[1172] 8.5.2 Product Servicing

[1173] A Hyperlabel™ tagged product item can contain a <servicing>button which, when activated using a netpage pen, or other suitablescanning device, signals that the user requires servicing of the productitem in question.

[1174] This may be achieved in a manner substantially similar to thatdescribed above with respect to product registration in either FIG. 101or 102, and the flow of information will not therefore be described indetail.

[1175] In this particular instance however, the registration requesttransferred from the pen server 500 to the manufacturer server 502 isreplaced with a service request, which will indicate at least theproduct ID or the product item ID of the item requiring servicing. Inthis instance, the manufacturer server 502 responds to the servicingrequest in such a manner as to provide required servicing of theproduct.

[1176] This can therefore be achieved in a number of ways depending onthe respective product item, the nature of the servicing required, andthe respective implementation.

[1177] For example, the manufacturer server 502 may be adapted toinitiate a standard response based on the item ID, and this willtherefore be performed in a manner similar to that shown in FIG. 101,with the manufacturer server 502 generating an indication of the actionto be taken as a response. This may include for example having anoperator contact the user of the netpage pen 101 to determine furtherdetails of the servicing required, and/or to schedule appointments.

[1178] Alternatively, the response may simply indicate to the user anumber to call to contact the manufacturer, or specify an appointedaction, such as returning the product item to a specified location.

[1179] Alternatively, the product item can include a number of buttonsindicative of respective faults. In this instance, the user will selecta button indicative of a respective fault using the netpage pen 101,with an indication of this being provided in the servicing request,thereby allowing the manufacturer server to determine an appropriateresponse action.

[1180] Thus, for example, the manufacturer server 502 can be providedwith details of respective action to be taken for each kind of faultindicated on the product item. Again, this may include for examplereturning the product for servicing, arranging for an engineer toservice the product, arranging for a portion of the product to bereplaced, or the like.

[1181] Alternatively, the <servicing> button may simply indicate thatservicing is required, with the manufacturer server 502 generating aservicing form which is transferred to a terminal, such as the printer601 described above. This is used to allow the manufacturer to obtaindetails of the servicing required, in a manner similar to the provisionof the further user details, as described with respect to FIG. 102above.

[1182] In this case, the servicing form may include details of the typeof servicing required by the user, such as an indication of the natureof the fault, preferred times and dates for servicing or the like. Theuser can complete the form using the netpage pen 101 with the pen server500 operating to forward on the details of the completed form to themanufacturer server 502. The manufacturer server can then arrange forservicing to be performed as required by the manufacturer.

[1183] 8.5.3 Communications Services

[1184] A further operation of Hyperlabel™ tagging is to provide the userwith access to services associated with the product item, such as forexample free communications. Again, this may be achieved by having theuser select a <communications> button provided on an interface surfaceassociated with the product item.

[1185] An example of how this may be achieved will now be described withreference to FIG. 102, and for the specific example of thecommunications being an SMS.

[1186] In particular, in this example, the product item 201 is providedwith an <SMS> button. In this instance, when the user wishes to send anSMS, they can select the <SMS> button utilising either the netpage pen101, or a mobile phone which is adapted to incorporate a netpage pen orpointer function and in particular to operate as in a manner equivalentto a netpage pen.

[1187] In this instance, the method will be substantially as describedabove with the pen server 500 obtaining a server address from the nameserver 501 and utilising this to obtain an interface description fromthe product server 251. The interface description will be used by thepen server 500 to determine that an <SMS> button has been activated,thereby indicating that user wishes to obtain a free SMS. Thus, the penserver 500 generates an SMS request which is transferred to themanufacturer server 502.

[1188] The manner in which the SMS is provided will vary depending onthe respective implementation.

[1189] In a first embodiment, the manufacturer server 502 will respondto the SMS request to provide the user with an SMS response inclusive ofa number to which the SMS should be sent.

[1190] The user simply generates an SMS in the usual way utilising theirown mobile phone, and including an indication of the intendeddestination phone number. The user then sends the SMS to the numberindicated in the SMS response to correspond to a number operated by themanufacturer, or other entity.

[1191] The manufacturer or other entity will receive the SMS and thenforward this to the destination number indicated in the SMS. Typically,the numbers will be configured so that the user is not charged for thisprocess and in return for this, the manufacturer will typically embedadvertising within the sent SMS, such as an indication that the SMS wassent in accordance with a free SMS provided by the respective entity.

[1192] In a second example, the user sends the SMS directly to thedestination in the normal way. In this case, the manufacturer server 502receives details of the user's mobile phone number as part of the SMSrequest, and arranges payment of the SMS on the user's behalf.

[1193] In a third example, the process operates without requiring directuser interaction with a mobile phone. In this instance, the <SMS> button512 is associated with a destination region 510 and a message region 511on the product item interface, as shown in FIG. 103.

[1194] In use, the user provides a hand-written indication of thedestination mobile phone number in destination region 510, and ahand-written indication of the message text in the message region 511.In this case, once this information has been completed, the user selectsthe <SMS> button 512 using the netpage pen 101, causing the netpage pen101 to transfer the item ID and digital ink, indicative of thedestination and message, to the pen server 500. In this instance, whenthe SMS request is transferred to the manufacturer server 502, this willinclude the destination number and message text which the manufactureruses to send the SMS accordingly.

[1195] In a fourth example, the user selects the <SMS> button, causingthe SMS request to be transferred to the manufacturer server 502. Themanufacturer server will then generate an SMS form, which is provided tothe user in a manner similar to that shown in FIG. 102. The user thenprovides the destination and message body details via the form, allowingthe manufacturer to send the SMS accordingly.

[1196] It will be appreciated that these techniques can also apply toother forms of communication, such as e-mail, MMS messages, or the like,as well as to making free phone calls, or the like, in which case boththe delivered message and the embedded advertising may include images,graphics, audio, video and Web page content”.

[1197] 8.5.4 Product Information via Product ID

[1198] Some of the benefits of Hyperlabel™ tagging products can begained by enhancing the netpage pen to decode UPC bar codes.Alternatively a UPC bar code scanner can netpage-enabled. When thenetpage system receives a scanned UPC, it forwards a request to adefault or favorite application for that product type (as describedearlier), and this in turn elicits product information from theapplication, such as in the form of a printed netpage. The product pagecan also include the facility to enter the serial number of the productitem and register the user's ownership of it via a <register> button.Product manufacturers can thus gain the benefits of netpage linking fortheir entire installed base of products without making alterations tothe products themselves.

[1199] 8.5.5 Context-Specific Product Help

[1200] If the entire surface of a product is Hyperlabel™ tagged, thenpressing on any part of the surface with a netpage pen can then elicitproduct-specific help. The help is either specific to the area pressed,by providing respective <information> buttons, or making respectiveregions of the product interface surface responsive to providerespective information, or relates to the product as a whole. Thus theuser of the product has instant access to helpful information aboutspecific features of a product as well as the product as a whole. Eachfeature-specific help page can be linked to the entire product manual.

[1201] It will be appreciated that this can be achieved in mannerssimilar to those described above with respect to FIGS. 101 and 102, withan indication of the selected region, button, or simply the item IDbeing transferred to the manufacturer server to allow the information tobe provided.

[1202] 8.5.6 Home Inventory

[1203] In a further example the system is adapted to provide homeinventory functionality by allowing a user to use a scanning device,such as a hand-held device described above with respect to FIGS. 58 to75, or a netpage pen 101, to update details of product items within thehome.

[1204] In one embodiment, when a user has purchases a product, they usethe netpage pen 101 to scan the coded data provided on the productitem's interface surface, thereby allowing the pen server 500 todetermine the item ID. An indication of this can then be stored in adatabase on a product item list, which lists items currently owned bythe user.

[1205] When the user uses the item, the product item can again bescanned, with the pen server 500 using the determined item ID to removethe product item from the product item list.

[1206] In the simplest embodiment, this therefore uses a singleundifferentiated scan process to both add and remove product items fromthe product item list. However, as this may lead to incorrect adding orremoval of items from the list, for example, due to double scanning ofan item, in an alternative embodiment, the scanning processes for addingand removing items from the list are differentiated, such that arespective scan operation is used to add and remove the product items.

[1207] In one example, this is achieved by providing respective <add>and <remove> buttons on the product item. In this instance, the userselects an appropriate button, with the identity of the button beingdetermined by obtaining an interface surface description from theproduct server 251, in a manner similar to that described above. The penserver will then add the item to, or remove the item from the productitem list as required.

[1208] As an alternative to providing respective buttons on the productitem interface surface, the sensing device can be adapted to operate indifferent modes, such as an “add to list” mode and a “remove from list”mode. Selection of an appropriate mode may be achieved using an inputprovided on the sensing device, or alternatively, by the use of asuitably encoded netpage which has buttons provided thereon. In thiscase, the pen server interprets the pen input in relation to theinterface description and as a result uses this to select a scanningdevice mode. Again, this will be achieved by having the pen server 500to obtain a page description from a page server, and use this todetermine the operating mode associated with the respective button.

[1209] In addition to maintaining a list of current items within thehome, the pen server 500 may also be adapted to store minimum stocklevel indications in the form of predetermined thresholds of certaintypes of product items. In this case, when the pen server 500 updatesthe product item list, the pen server will determine the type of theproduct item added or removed from the product item list, and uses thisto update a total of the number of product items of the respective type.This value is then compared to the predetermined threshold associatedwith the respective product item type. If the number of product items isbelow the threshold, an appropriate indication is generated that theproduct item requires replenishment.

[1210] This can be achieved by adding an indication of the product itemto a shopping list, which is therefore automatically updated withdetails of product items that need replenishing. Accordingly, thisallows the pen server 500 to maintain an inventory of product itemscurrently in the home and obtain a shopping list of items that are ofstock below a predetermined level.

[1211] In the above examples, the functionality of maintaining theinventory is typically performed by an inventory application operatingon a suitable computer system, such as a computer owned by, run by,and/or situated in the user's home. In this case, the pen server (orpage server) operates to interpret digital ink and submit this to theapplication. In use, when the user goes shopping, the shopping list maybe printed out in the form of a netpage, with the product item types andnumber of the product items required being indicated by the coded dataprovided thereon. This can then be used to ensure that correct items arepurchased in the shop by scanning the shopping list, and then scanningselected product items, to allow these to be removed from the list.

[1212] Alternatively, the shopping list may be used to place an onlineorder, either automatically, for example on a regular basis, or at theuser's direction.

[1213] A number of other variations are also possible. For example, thepen server 500 can be adapted to record details of the status of productitems within the home, such as defining product items as in use.Furthermore, product items may also be added directly to shopping listsupon use (i.e. instead of maintaining a home inventory), again byselection of an appropriate input mode, through the use of a button onthe product item or the like.

[1214] 8.5.7 Product Ownership Tracking

[1215] If the entire surface of a product is Hyperlabel™ tagged, thenpressing on any part of the surface with a netpage pen can elicit adescription of the product and its current ownership. After the productis purchased, pressing on any part of the surface can automaticallyregister the product in the name of the owner of the netpage pen. Anyonecan determine the ownership of a product offered for sale simply bypressing on any part of its surface with a netpage Pen. Ownership mayonly be registered by a new owner if the current owner has relinquishedownership by signing the “sell” portion of the product's status page.This places the product in an “un-owned” state.

[1216] Product information and ownership is maintained either by theproduct manufacturer, as a service to its customers, or by aprofit-oriented third party.

[1217] The shipping computer system of a product manufacturer canautomatically transfer ownership of products from the manufacturer tothe distributor or retailer, and so on down through the supply chain.The retail computer system of the retailer can automatically mark eachsold item as free, or transfer ownership directly to the holder of thepayment card used to pay for the product. The customer can also use anetpage pen at the point of sale to register immediate ownership of theproduct.

[1218] Traditional clearing-houses for stolen goods, such as pawn shops,can be required by law to check the ownership of all products presentedto them. Since a Hyperlabel™ tagged product has an invisible encoding onmost or all of its surface, it is difficult for a thief to remove it oreven tell if it has been successfully removed. Conversely, it isincumbent on a potential buyer of a product to ensure that a cleanreading can be obtained from its surface so that its ownership can beindisputably established.

[1219] Where a product is leased or otherwise subject to complex ormultiple ownership, the product registration database can reflect thisand thus alert a potential buyer.

[1220] 8.5.8 Light Weight Web Interface

[1221] As described earlier, Hyperlabel™ tagged products can be used torequest linked Web pages for printing or display on a Web terminal, e.g.a screen-based Web browser running on a personal computer (PC), mobiletelephone or personal digital assistant (PDA).

[1222] In the absence of infrastructure support for product interfacedescriptions, a single page ID can be used per page, or an individuallink ID can be used for each embedded hyperlink, i.e. the position 86usually encoded in a netpage tag (or Hyperlabel™ tag) can be replaced bya link number, either selectively or over the entire page.

[1223] If the page ID is structured (e.g. if it includes an item ID215), then part of the page ID (e.g. the product ID 214) can be used toidentify a Web page directly, i.e. via some rule for encoding the ID asan Uniform Resource Identifier (URI), and the remaining part (e.g. theserial number 213) can be appended to the URI as a unique session ID(transaction ID). The presence of the session ID can allow thecorresponding Web server to enforce per-item behavior, such as ensuringthat a competition is only entered once. If link numbers are used, thenthey also form part of the URI.

[1224] 8.5.9 Local Computer Application Interface

[1225] The user interface to a GUI-based computer application running ona multi-tasking computer can be printed as a netpage on a user interfaceor command “card”. The printed user interface can include a “digitizerpad” area for moving the GUI pointer relative to the application.Invoking any function of the application's user interface or moving theGUI pointer, automatically makes the application current—i.e. if theapplication is running in a windowed GUI system then its window isbrought to the front and made current. If the application is notcurrently running, then it is automatically launched.

[1226] The printed user interface for a text-oriented application cancontain a printed keyboard, a general-purpose handwriting input textfield, or both.

[1227] A personal computer system or workstation can thus potentiallyconsist of a screen for displaying GUI output, a number ofapplication-specific printed user interfaces, a sensing device(typically a stylus) for sensing user operations relative to the printeduser interfaces, and a computer which receives wired or wirelesstransmissions from the sensing device, runs applications, and interpretssensed inputs relative to each application.

[1228] Each printed user interface “card” can be encoded with a uniquepage ID specific to the application, and tagged with an attribute whichinstructs the personal computer or workstation to interpret operationson the page relative to a local instance of the application, even in aglobal networked netpage environment.

[1229] If the computer is a network terminal connected to a LAN, anintranet, or the Internet, any interaction with the printed userinterface can launch or interact with a networked instance of theapplication.

[1230] 8.5.10 Sensing Device Context

[1231] The same netpage may elicit different behavior depending on thetype, identity and/or context of the netpage sensing device used tointeract with it. For example, a netpage pen or stylus connected to a PCor Web terminal without a netpage printer (or prior to full netpagesystem deployment) may elicit displayed Web pages or even localapplication behavior, as described above.

[1232] In the presence of a netpage printer the same sensing device mayelicit printed netpages, possibly with a different format and behaviorto the corresponding on-screen versions.

[1233] 8.6.1 Orientation Determination

[1234] It will be appreciated that by providing an interface surfaceover a substantial portion of a product item or other object, and byutilising the positional information encoded in the coded data providedthereon, this allows the orientation of the product item or object to bedetermined.

[1235] In particular, if the object is scanned by a scanning systemwhose location is known, such as the scanning system described withrespect to FIG. 82, detecting a coded data tag allows the pen server 500to access the interface surface page description, from the productserver 251, and use this to determine the location of the tag on theobject.

[1236] In addition to this, the tag also encodes orientationinformation. Accordingly, by determining the orientation of the tag, andcombining this with information regarding the position of the sensed tagon the interface surface, this allows the position and orientation of anobject to be determined.

[1237] Thus, it will be appreciated that this is similar to determiningthe position and orientation of a netpage pen 101 with respect to anetpage, albeit with the scanning device remaining stationary whilst theobject and the associated interface surface move.

[1238] In a variation on the above described technique, particularlywhere a high degree of accuracy is not required, or if it is merelyrequired to determine which way up an object is, for example todetermine on which face a box is resting, each face of the box can beencoded as a respective region provided on the interface surface. Thisis achieved by assigning a respective region ID to each tag on arespective face of the box or other object.

[1239] In this case, the scanner can be positioned so as to detect datatags on one face, such as the top of the object. In this case, theregion ID determined from the detected tag will be used to access aninterface surface description in the usual way, with description simplyindicating a respective surface of the object in accordance with theregion ID, thereby allowing the orientation of the object to bedetermined.

[1240] In a further example, the region ID encoded in the coded data candirectly indicate the face of an object, such as the top, side, bottom,as well as an orientation with respect to a nominal reference. Thisallows the orientation of the object to be determined directly from thecoded data without reference to a description of the object, or aninterface surface description.

[1241] In the event that the absolute position of the tag on theinterface surface is not required, then it is possible to useobject-indicating tags instead of position-indicating tags.

[1242] 8.6.2 Assembly/Packing System

[1243] It will be appreciated that the orientation determining systemdescribed above can be used to pack objects, as well as to assembleobjects from component parts.

[1244] An example of this will now be described with reference to FIG.104, in which an object 6001 is transported on a conveyor 6002 through asensing region 6003 generated by a scanning device 6004. In thisexample, the object 6001 is to be packed into a box 6011, transportedvia a conveyor 6012 through a sensing region 6013 generated by ascanning device 6014. In this example, the scanning devices 6004, 6014are formed from scanning devices similar to that described with respectto FIG. 82.

[1245] In addition to this, a robotic packing system formed from a robotarm 6020, having a manipulator 6021, which is provided to allow theobject 6001 to be packed into the box 6011. The arm may be any form ofarm, as described for example in U.S. Pat. No. 4,259,876.

[1246] In use, this is achieved by having the scanning device 6004 senseHyperlabel™ tags provided on the surface of the object, thereby allowingorientation and position of the object 6001 to be determined, using thetechniques described above. Similarly, the scanning device 6014 is usedto determine the orientation and position of the box 6011 usingHyperlabel™ tags provided thereon.

[1247] Signals from the sensing devices regarding the orientation andposition of the object 6001 and the box 6011 are then transferred to acontrol system 6022, which operates to cause the robotic arm 6020 topick up the object 6001 using the manipulator 6021 and insert the objectinto the box 6011.

[1248] It will be appreciated that this form of position determinationto allow packing of objects can be utilised in any form of genericpacking system as the nature of the robotic system is not important forthe purposes of the present invention. It will therefore be appreciatedthat the techniques can be used in any packing system, such as thepacking system described in U.S. Pat. No. 5,165,219, whilst avoiding theneed for complex orientation determination as described therein.

[1249] It will be appreciated that as a variation, the system can beadapted to assemble complex objects from component parts. Thus, forexample, the conveyors 6002, 6012 can be adapted to carry respectivecomponent parts, with the scanning devices 6004, 6014 being used todetect the position, orientation and identity of the component parts, asdescribed above. Once the component parts have been determined, thecontrol system 6022 determines in accordance with predetermined assemblyinstructions, the manner in which the component parts should be combinedto form the complex object. The robotic arm 6020 can then be operated toin accordance with the assembly instructions and the orientation andposition of the respective component parts, thereby allowing the objectto be constructed.

[1250] It will be appreciated that in such cases, it is typical torequire more than one robotic arm, and potentially other manipulatingdevices for performing specific operations, such as welding of thecomponent parts.

[1251] Thus, this system allows components, such as car parts or thelike, to have coded data disposed thereon at certain predeterminedlocations. The coded data may be disposed by printing, etching, or thelike. The car part would then be scanned by an appropriate scanningdevice to allow its exact orientation to be determined, allowing theparts to be assembled into a car.

[1252] It will be appreciated that this form of position determinationto allow components to be assembled into an object can be utilised inany form of generic robotic system as the nature of the robotic systemis not important for the purposes of the present invention. It willtherefore be appreciated that the techniques can be used in any roboticassembly system, such as the system described in US-2004016112.

[1253] This therefore prevents the need for precise vision systems, suchas that described in U.S. Pat. No. 5,943,476, which are often extremelyexpensive and often unreliable.

[1254] Again, coded data can directly indicate the face of an object orcomponent, such as the top, side, bottom, as well as an orientation withrespect to a nominal reference. Similarly, it is possible to useobject-indicating tags instead of position-indicating tags, to sense theposition and/or orientation of the component or object.

[1255] 8.7.1 Shopping Receptacle

[1256]FIG. 105 shows a shopping trolley or cart 6100 fitted with one ortwo scanning devices 6101, which operate to sense product items 201positioned in a sensing region 6102 corresponding to the opening of theshopping receptacle. It will be appreciated that the scanning device(s)may be similar to the scanning devices described above.

[1257] In any event, as product items are inserted into the receptacle6100, the scanning device(s) 6101 scan the product item and detect codeddata tags provided thereon, allowing the item ID of the product item tobe determined. It will be appreciated that this may provide a variety offunctionality to the shopper.

[1258] In particular, in a first example, an associated computer systemadds an indication of the scanned product item to a purchase list, whichstores an indication of each product item added to the receptacle. Thisallows the user to automatically scan items when they are placed in theshopping receptacle, allowing them to be subsequently purchased in somemanner.

[1259] Thus, when a user has selected all the product items required,the scanning device 6101 can be adapted to determine a cost of all theproduct items thereby allowing payment to be made. It will beappreciated that this may be achieved in any one of a number of mannersdepending on the situation.

[1260] For example, the user may present their receptacle to a cashierwho will determine an indication of the cost of the items from thecomputer system, thereby allowing payment to be collected. In this case,if the computer system is provided on the receptacle itself, this can beachieved by having the cashier interrogate the computer system using asuitable communications system.

[1261] Alternatively, the computer system may be provided centrally,thereby allowing a single computer system to monitor lists for each ofthe receptacles in a store. In this instance, when the scanning device6101 detects the addition of the product item to the receptacle, anindication of the item ID, together with an identifier associated withthe receptacle will be transferred to the computer system, therebyallowing the computer system to maintain a respective list associatedwith each receptacle. In this instance, the cashier will determine thelist for a respective receptacle by providing an indication of theidentity of the receptacle to the computer system, thereby allowing thecomputer system to retrieve the relevant purchase list.

[1262] A number of variations on the above are also possible.

[1263] For example, the scanning device 6101 can be provided with a userinterface, such as a touch sensitive display, thereby allowing the listto be displayed to the user. This also allows product item informationto be determined by placing the product item in the sensing region 6102.In this example, the product information may include information such asthe:

[1264] manufacturer;

[1265] item identity;

[1266] expiry date;

[1267] nutritional information; and,

[1268] or any other appropriate information.

[1269] The user interface may also allow the user to make controlinputs, such as to select articles on the purchase list, allowingfurther information to be provided, or the like.

[1270] In one example, product items are added to the list when placedinto the receptacle and removed from the list once removed from thereceptacle. However, as an alternative, the user may be required toenter a special mode to thereby remove items from the list.

[1271] It will be appreciated that the receptacle may be in the form ofa basket as shown in FIG. 107.

[1272] 8.7.2 Shopping Receptacle Incorporating Scales

[1273] In a further embodiment of the shopping receptacles, the shoppingreceptacle is further modified to include a weighing device, such aselectronic scales, shown generally at 6105 in FIG. 108. In this example,the weighing device operates to weigh the product items placed in thereceptacle as each product item is placed therein. The weight determinedby the weighing device is then compared to a predetermined weightindicated for the product item.

[1274] Thus, the computer system will use each item ID to access datastored in a store which indicates the weight of the respective productitem. It will be appreciated that this may be provided in the productinformation. The weight determined using the item ID is then compared tothe weight determined by the weighing device 6105.

[1275] In the event that the scanned product item and weight of productitems inserted into the receptacle do not agree, this indicates thatthere has been a scanning error, or that the user has attempted toinsert more than one item into the receptacle, to thereby disguise thepresence of one of the items, allowing the item to be fraudulentlyobtained. In the event that such a disparity is determined then anindication of this will be provided allowing the user to correct thescanning error.

[1276] In the event that this is not corrected, an alert can beactivated, allowing the contents of the user's receptacle to be checkedby shopping assistants in-store, security or the like.

[1277] 8.7.3 Shopping Receptacle/Scanner Association

[1278] In one example, the shopping receptacle 6100 is associated with auser prior to commencing shopping. This may be achieved for example byhaving the user present an identity card to the scanning device 6101, asdescribed in more detail below.

[1279] In this instance, the scanning device 6101, upon determining theuser identity, will transfer an indication of this in the form of a userID, together with a shopping receptacle ID, to a computer system. Thismay be the same computer system which retains the details of thepurchase list. In any event, when the user completes shopping, thisallows the total of the product items purchased to be determined fromthe computer on the basis of the user's identity.

[1280] Thus, it will be appreciated from this, that the shoppingreceptacle becomes associated with the identity of the user so as todefine a shopping session. At the end of the shopping session, when theuser has selected all the product items required and arranged payment,the receptacle is disassociated from the user.

[1281] This allows systems of automated payment to be implemented. Forexample, the user can place product items for purchase in the shoppingreceptacle and walk through an exit station. On walking through the exitstation, the scanning device 6101 transmits information concerning theproduct items purchased and the shopping receptacle identity to apayment server. The payment server determines the identity of the userassociated with the respective shopping receptacle, and operates todebit an account of the user accordingly, thereby providing an automatedcheckout facility.

[1282] In addition to this, it is possible for the user to be providedwith personalised information via the user interface. For example, theuser can register details of allergies, such as nut allergies, with thestore. In this case, when the user has been associated with areceptacle, if a product item contains a relevant ingredient, such asnuts, a warning can be provided to the user.

[1283] In addition to this, advertising, details of special offers, orthe like, can be provided via the user interface, with this informationbeing tailored to user preferences, or the like.

[1284] As an alternative to providing a scanning device associated witha shopping receptacle, it is also possible to provide a handheldscanning device which is used by users to scan select items placed in anormal receptacle. In this case, a record of the product items scannedfor purchase is stored in a memory in the scanning device, or iswirelessly transferred to a suitable computer system which stores arecord associated with the identity of the scanning device, or the user.Upon leaving the store, the user relinquishes the scanning device, andis charged accordingly for those product items purchased using thescanning device. This may be achieved, for example, by using the user'sidentity to determine a charge account which can be used to makepayment.

[1285] 8.7.4 Card Encoding

[1286] An example of a card which may be utilised with the systemdescribed above will now be described with respect to FIG. 109. Inparticular, the loyalty card can be any form of credit card size cardformed typically from a plastic substrate, or the like. The card mayinclude information such as the user's name 6150, signature field 6151,and optionally other security information such as holographic tags 6152or a magnetic stripe 6153 with information encoded thereon.

[1287] Coded data 6154 is disposed over a substantial area of the card,as shown at 6154. In use, the coded data is used to encode dataindicative of a user identity, such as a netpage user ID or alias ID, asdescribed above.

[1288] This is typically achieved by using a card blank, including thesecurity information thereon. The card may then be printed or embossedwith the user's name, before or after being printed or embossed with thecoded data. In addition to this, the process may also additionally, oralternatively, involve encoding additional information in the magneticstripe. The card is then issued to the user, allowing the user to signthe card in the signature field.

[1289] The card may also include additional information disposedthereon, such as the user information, a logo of a retailer, othersecurity information, a name of a retailer, or the like. Thisinformation may again be printed using visible ink, either before orafter the printing of the coded data.

[1290] In use, the store can use the sensed coded data to identify theuser and determine details or payment information, or the like.

[1291] 8.8 Near-Infrared Dyes

[1292] Near-infrared dyes suitable for Hyperlabel™ tagging (and netpagetagging in general) exhibit relatively strong absorption in the nearinfrared part of the spectrum while exhibiting relatively minimalabsorption in the visible part of the spectrum. This facilitates tagacquisition under matched illumination and filtering, while minimisingany impact on visible graphics and text.

[1293]FIG. 93 and FIG. 95 show the molecular structures of a pair ofsuitable near-infrared dyes.

[1294]FIG. 93 shows the structure of isophorone nickel dithiolate. Asshown in FIG. 94, it exhibits a strong absorption peak around 900 nm inthe near infrared, while exhibiting relatively minimal absorption in thevisible spectrum.

[1295]FIG. 95 shows the structure of camphor sulfonic nickel dithiolate.As shown in FIG. 96, it exhibits a strong absorption peak just below 800nm in the near infrared, while exhibiting relatively minimal absorptionin the visible spectrum.

[1296] 8.6 Hyperlabel™ Tagging Benefits

[1297] Some of the benefits of Hyperlabel™ tagging will now bediscussed. This will focus on the costs and benefits of item-leveltagging using Hyperlabel™ tag-carried EPCs in grocery. Note, however,that Hyperlabel™ tags are also applicable to higher-valued items, anditems which are tagged with RFIDs may usefully be Hyperlabel™ tagged aswell to allow scanning without RFID infrastructure or after RFIDerasure.

[1298] Assuming case-level RFID tagging and item-level Hyperlabel™tagging, an item is accurately recorded into retail store inventory whenits corresponding case is received and scanned. Ignoringstocktake-related scanning for the moment, the item is next scanned atthe checkout, at which time it is recorded as sold and removed fromon-hand store inventory.

[1299] A grocery checkout system based on optical reading of Hyperlabel™tags, such as the system described above can provide equivalentcapabilities. Grocery item labels and packaging are particularlywell-suited to Hyperlabel™ tagging, where much or all of the visiblesurface of a product item can be tagged. A Hyperlabel™ reader canreliably scan a Hyperlabel™ tagged product item presented in its fieldof view, irrespective of the item's orientation. If an item insteadcarried only a single visible bar code (whether UPC or unique), thenreliable scanning would only be achieved by presenting the item's barcode directly to the reader, as occurs at checkouts at present. Thiswould in turn preclude automatic scanning.

[1300] In practice a Hyperlabel™ reader is designed to scan the scanningfield from at least two substantially orthogonal directions. This helpsthe reader scan items which are only partially Hyperlabel™ tagged, suchas tins which may have untagged tops and bottoms, and can also help thereader avoid occlusions which may occur in manual presentationscenarios, i.e. due to the hand presenting the item to the reader.

[1301] Since partial and incremental item-level RFID tagging ofhigher-value grocery items is likely, in practice a checkout mayincorporate both RFID and Hyperlabel™ readers. Since Hyperlabel™ taggingmay itself be introduced incrementally, a checkout may incorporate RFID,Hyperlabel™ and bar code reading ability.

[1302] Automatic checkouts bring a number of benefits. They reduce staffcosts by reducing reliance on trained checkout operators, both byreducing required skill levels at manned checkout stations, and byfacilitating simplified self-checkout by customers, thus increasing itsacceptance. In addition, automatic checkouts minimise the possibility ofcollusion between the operator and the customer, i.e. where the operatordeliberately omits scanning selected items, thus resulting in reducedshrinkage.

[1303] Self-checkout has the intrinsic benefit that a single operatorcan oversee multiple self-checkout stations. Since scan errors are morelikely during self-checkout than during manned checkout, self-checkoutstations incorporate scales which allow an item's weight to becross-checked against the item's scanned class. This also helps toprevent substitution-based cheating by the customer. Item-level taggingmakes scanning more accurate, and makes substitution more difficult,since the substituted item must be an unsold item in the store'sinventory, and can only be used once.

[1304] Once an item is in the customer's hands, the item's EPC can serveas a link to useful item-related online information. This is discussedin detail later in a companion paper.

[1305] When an item is shoplifted or otherwise stolen from a store, itremains recorded as part of the store's on-hand inventory. In the caseof item-level RFID tagging, theft can arguably be detected by RFIDreaders strategically positioned at store exits. However, a shoplifteror thief can exploit RFID readers' problems with radiopacity byshielding the stolen item's RFID tag from exit readers. Once at large,however, the stolen item's EPC acts as a persistent link to informationwhich indicates that the item has not been legitimately obtained. Thisauditability of any item serves as a powerful deterrent to shopliftingand theft, including the acquisition of goods whose providence issuspect. Note that this applies equally to items shoplifted via anauto-checkout.

[1306] If and when the customer decides to return alegitimately-purchased item to a retail store because the item isunwanted, unsuitable or defective, the EPC serves as a link toinformation which confirms that the item has been legitimately obtainedfrom the same store or the same retail chain. This prevents fraudulentreturns, such as the attempted “return” of stolen goods, and ensuresthat any credit associated with a legitimate return matches not thecurrent price but the original purchase price, which may besubstantially different. The EPC also allows the return to be accuratelyrecorded, so that the returned item itself is less likely to be subjectto internal loss or theft.

[1307] With item-level tagging, inventory records intrinsically becomemore accurate, with the consequence that automatic reordering andreplenishment becomes more reliable and hence relied-upon. This in turnimproves stock availability while simultaneously reducing reliance onsafety stock. Demand-driven efficiencies then flow back up the supplychain.

[1308] Case-level RFID tracking in the backroom, coolroom and freezer,either during case movement or in situ, allows accurate backroom stockmonitoring. Case-level RFID tracking onto the sales floor allowsaccurate recording of shelf-stock additions, and item-level tracking atthe checkout allows accurate recording of shelf-stock removals.

[1309] Imminent out-of-stock conditions on the sales floor are rapidlydetected from on-shelf stock levels, and replacement stock availabilityin the backroom is rapidly determined from backroom stock levels, aswell as the approximate or exact location of the replacement stock inthe backroom.

[1310] Unlike with UPCs, poor shelf stock rotation is easily detectedvia item-level tracking at the checkout. If newer stock of a product isinadvertently sold in preference to older stock, then a stock rotationalert can be raised for the product in question. Shop staff caninterrogate the shelf stock in question using hand-held scanners toobtain date codes, or can read date codes directly off the stock. Poorstock rotation is thereby addressed before the stock in question becomesunsaleable, leading to a general reduction in the unsaleable rate.

[1311] Relatedly, Hyperlabel™ tagging makes it possible to constructsmart dispensers for high-value and high-turnover items whichincorporate Hyperlabel™ readers and monitor all dispensing andreplenishment operations to allow imminent out-of-stocks to be signalledand sweeps to be detected.

[1312] Hyperlabel™ tagging, in contrast to RFID tagging, is likely costsignificantly less than one cent once established, and to becomenegligible in the longer term, particularly once digital printing ofproduct labels and packaging becomes established. It is therefore likelythat item-level Hyperlabel™ tagging in the grocery sector is justified.

[1313]FIG. 97 shows the threshold cost of a tag as a function of costsavings projected as accruing from item-level tagging. Assuming wildlyoptimistic cost savings of 50% accruing from item-level tagging, thethreshold cost of a tag is just over two cents. Assuming more realisticbut still quite optimistic cost savings of 25%, the threshold cost of atag is just over one cent.

[1314] Whilst the read-only nature of most optical tags has been citedas a disadvantage, since status changes cannot be written to a tag as anitem progresses through the supply chain. However, this disadvantage ismitigated by the fact that a read-only tag can refer to informationmaintained dynamically on a network.

[1315] As noted earlier, if incremental tagging of higher-priced groceryitems takes place, then the average price of remaining grocery items isreduced, and the threshold cost of a tag is further reduced as well.This makes universal item-level RFID tagging even less likely, and makesa case for the use of Hyperlabel™ tagging as a lower-cost adjunct toRFID tagging.

[1316] 8.6.1 Shrinkage

[1317] The cost of shrinkage in the grocery sector was 1.42% of netsales in 2001-2002, equating to about $7 billion. The cost of shrinkagetherefore exceeded net profit. Table 5 summarises sources of shrinkagein the grocery sector. TABLE 5 Sources of shrinkage in the grocerysector approximate source of cost shrinkage contribution ($millions)internal theft 62.0% 4,340 external theft 23.0% 1,610 supplier fraud 7.6% 530 paper shrinkage  7.4% 520 total  100% 7,000

[1318] The largest source of shrinkage in the grocery sector, at 62% oraround $4.3 billion, is internal theft, consisting mainly of producttheft by employees. This is followed, at 23% or around $1.6 billion, byexternal theft, consisting mainly of shoplifting. Supplier fraud andpaper shrinkage together account for the final 15% or $1 billion.

[1319] Table 4 summarises the ways in which item-level RFID tagging canbe used to address the various sources of shrinkage, as described inAlexander, K. et al., Applying Auto-ID to Reduce Losses Associated withShrink, MIT Auto-ID Center, November 2002,http://www.autoidcenter.org/research/IBM-AUTOID-BC-003.pdf. The tablealso shows how item-level Hyperlabel™ tagging can in many caseseffectively address the same issues.

[1320] As shown in the table, item-level RFID addresses employee theftand shoplifting predominantly via exit-door RFID readers which detectattempts to remove unsold goods, while Hyperlabel™ tagging acts adeterrent to theft since item-level tagging supports downstream auditingof suspected stolen goods.

[1321] As described earlier, item-level scanning at point-of-saleimproves accuracy and enables automatic scanning, while item-levelrecording of sales prevents attempted fraudulent returns, both largelyindependently of tagging method. Automatic checkout scanning in turnreduces collusion between checkout operators and customers. TABLE 6Sources of shrinkage, RFID solutions and Hyperlabel ™ solutions sourceof RFID Hyperlabel ™ shrinkage pain point solution solution internaltheft product theft exit door audit scan N/A deterrent; N/A^(c)collusion with automatic automatic customers checkout checkout^(d)collusion with N/A^(c) N/A^(c) vendors external theft shoplifting exitdoor audit scan^(b) deterrent fraudulent item status item returns checkstatus check burglary audit audit deterrent; deterrent; N/A^(c) N/A^(c)supplier fraud phantom delivery N/A^(c) N/A^(c) invoice errors N/A^(c)N/A^(c) returns item status item status update update over/under N/A^(c)N/A^(c) delivery paper pricing errors N/A N/A^(e) shrinkage scanningerrors automatic automatic checkout^(d) checkout^(d) unrecorded itemstatus item status returns update update incorrect store automaticautomatic physical stocktake^(b); checkout^(d) inventory automaticcheckout^(d)

[1322] 8.6.2 Unsaleables

[1323] The cost of unsaleables in the grocery sector was 0.95% of netsales in 2001-2002 Lightburn, A., 2002 Unsaleables Benchmark Report,Joint Industry Unsaleables Steering Committee 2002, equating to about $5billion. The cost of unsaleables was therefore almost comparable to netprofit. Table 7 summarises sources of unsaleables in the grocery sector.TABLE 7 Sources of unsaleables in the grocery sector approximate sourceof cost unsaleable contribution ($millions) damaged 63% 3,150out-of-code 16% 800 discontinued 12% 600 seasonal  6% 300 other  4% 200total 101%  5,050

[1324] The largest cause of unsaleables in grocery, at 63% or over $3billion, is damaged product. This includes product which is unlabelled,improperly sealed, over- or under-weight, only partially filled,crushed, dented or collapsed, swollen or rusted (cans), moldy, leaking,soiled, stained or sticky.

[1325] Much of this damage is due to poor transport and handling, anditem-level tagging helps by allowing the supply-chain history of adamaged item to be queried. Over time this can pinpoint a particularproblem area, such as a specific distribution center where stafftraining is inadequate, or a specific forklift operator who needs totake more care. Furthermore, item-level tagging makes it feasible tofeed remedial information back to the appropriate point in the supplychain, including as far back as the original manufacturer or one of itssuppliers.

[1326] The second-largest cause of unsaleables in grocery, at 16% oraround $800 million, is out-of-code (i.e. expired) product. Item-leveltagging supports better stock rotation, for example via checkout-drivenalerts. Discontinued and seasonal product is more of a problem in retailsectors such as consumer electronics and apparel Alexander, K. et al.,Applying Auto-ID to Reduce Losses Associated with Product Obsolescence,MIT Auto-ID Center, November 2002,http://www.autoidcenter.org/research/IBM-AUTOID-BC-004.pdf, but stillaccount, at 12% and 6% respectively (or around $600 million and $300respectively), for a non-trivial proportion of grocery unsaleables.Discontinued product includes product withdrawn by manufacturers, andproduct made unsaleable by labelling and SKU changes due to mergers andacquisitions.

[1327] Item-level tagging helps reduce safety stock and so reducesexposure to discontinued and seasonal product. By improving stockvisibility, it makes offloading of soon-to-discontinued or seasonalproduct more efficient, i.e. without requiring excessive markdowns ormanufacturer returns. Finally, by improving auditability, it allowsbetter accounting of discontinued and seasonal stock back to theoriginal manufacturer, rather than forcing reliance on inefficient swellallowances Reilly, D., “Retail returns—a necessary problem, a financialopportunity”, Parcel Shipping & Distribution.

[1328] 8.6.3 Out-of-Stocks

[1329] Out-of-stocks were estimated to result in a 3% loss in net salesin 2001-2002 [25], which translates into a $200 million reduction in netprofit, or about 0.04% of net sales.

[1330] Although out-of-stocks have a much smaller effect on the bottomline than shrinkage and unsaleables, they are felt particularly acutelybecause they demonstrably undermine customer loyalty to brand, store andchain, and are considered eminently correctable. Table 6 summarises theways in which case-level and item-level RFID tagging can be used toaddress the various causes of out-of-stocks, as described in Alexander,K. et al., Focus on Retail: Applying Auto-ID to Improve ProductAvailability at the Retail Shelf, MIT Auto-ID Center, June 2002. Thetable also shows how item-level Hyperlabel™ tagging, in conjunction withcase-level RFID tagging, can in many cases effectively address the sameissues. TABLE 8 Sources of out-of-stocks, RFID solutions andHyperlabel ™ solutions RFID Hyperlabel ™ pain point solution solutionreceiving accuracy case-level case-level tracking and some tracking^(b)item-level tracking on-hand stock case-level case-level visibilitytracking^(b) and item- tracking^(b) and item- level tracking using leveltracking at smart shelves and the checkout at the checkout replenishmentfrom case-level tracking^(b) case-level the backroom and item-leveltracking tracking^(b) plan-o-gram manual and manual compliance/ smartshelves^(c) product lifecycle management cycle counting/manual manualand manual ordering errors smart shelves^(c) physical inventory manualand manual counts (preparation smart shelves^(c) and execution)point-of-sale automatic automatic scan accuracy checkout checkout^(d)inaccurate automatic automatic replenishment checkout checkout^(d)algorithms

[1331] 8.6.4 Privacy Implications of Item-Level Tagging

[1332] An RFID tag is promiscuous in that it responds with its ID to aquery from an RFID reader without verifying the reader's right to ask.When a uniquely tagged item is travelling through the supply chain andbenefits from being tracked, this promiscuity is useful, but once theitem is purchased by a customer and no longer needs to be tracked, itcan become a problem. The owner of the item may have no idea that theitem's RFID tag is being queried surreptitiously, since the readerdoesn't require line-of-sight to the tag. Even low-cost passive tagsintended for high-volume tagging of product items can be read from adistance of at least a meter, and in many cases much further. If theRFID tag contains a unique item ID, then for tracking purposes the itemID becomes a pointer to the person, particularly if the RFID is embeddedin clothing, shoes, a wristwatch or jewellery.

[1333] RFIDs typically support a partial or complete self-erasurecommand, and it is proposed that RFIDs should be at least partiallyerased at point-of-sale to remove an item's serial number (but notnecessarily its product number). It is also proposed, in an “RFID Billof Rights”, that such erasure should be the prerogative of the customer.It is still unclear whether retailers will erase tags by default or evengive customers a choice.

[1334] Even if serial numbers are erased at point-of-sale, the“constellation” of product codes readable from the various RFID tagscarried by a particular person may still constitute a sufficientlyunique signature for tracking purposes.

[1335] Hyperlabel™ tags are less promiscuous than RFIDs since theyrequire line-of-sight for reading. Unlike RFID tags which are likely tobe physically embedded in product during manufacture, Hyperlabel™ tagsare likely to only appear on labels and packaging, which in the case ofhigher-priced items such as clothing and shoes is typically removed fromthe product prior to use.

[1336] Where Hyperlabel™ tags persist on higher-priced product items,they typically do so in discreet locations such as on labels sewn intothe seams of clothing. For lower-priced items such as grocery, thepersistence of item-level tagging is not a threat to privacy.

[1337] If privacy advocates succeed in forcing RFIDs to be erased atpoint-of-sale by default, then dual RFID tagging and Hyperlabel™ taggingprovides a way of providing consumers with the downstream benefits ofitem-level tagging without the privacy concerns of RFID, includingonline access to item-specific product information, as well as validatedreturns, warranties and servicing.

[1338] 8.6.5 Conclusion

[1339] Accordingly, Hyperlabel™ tags provide a useful technique foritem-level product tagging.

[1340] In particular, Hyperlabel™ tagging is inexpensive, making iteconomically viable for product items priced below a threshold value ofa few dollars, such as the average grocery items, unlike RFID tags. Inthe grocery sector in particular, this provides many benefits such asreducing shrinkage, unsaleables and out-of-stocks.

[1341] In addition to this however, Hyperlabel™ tags provide consumerswith the downstream benefits of item-level tagging such as the provisionof additional interactivity, including the ability to define multipleinteractive regions on product labels or packaging, which makes the useof Hyperlabel™ tagging preferable to the use of RFID tags.

[1342] It will be appreciated however that in some circumstancesHyperlabel™ tagging can be used in conjunction with RFID tagging.

[1343] Although the invention has been described with reference to anumber of specific examples, it will be appreciated by those skilled inthe art that the invention can be embodied in many other forms.

1) A method of maintaining a status of a product item, the product itemincluding an associated interface surface, the interface surface havingdisposed thereon or therein coded data including a plurality of codeddata portions, each coded data portion being indicative of an identityof the product item, the method including, in a sensing device: (a)sensing at least one coded data portion; (b) generating, using thesensed coded data portion, indicating data indicative of the productitem identity; and, (c) transferring the indicating data to a computersystem, the computer system being responsive to the indicating data toupdate product status information stored in a data store. 2) The methodof claim 1, the product status information indicating for at least oneproduct item, the product item identity and the status of the productitem. 3) The method of claim 1, wherein the method includes, in thesensing device: (a) sensing at least one coded data portion; and, (b)generating the indicating data using the sensed coded data portion. 4)The method of claim 1, wherein each coded data portion is indicative ofthe respective position, and wherein the method includes, generating inthe sensing device and using the sensed coded data portion, indicatingdata indicative of at least one of: (a) a position of the sensed codeddata portion on the interface surface; and, (b) a position of thesensing device relative to the interface surface. 5) The method of claim4, wherein the method includes, in the computer system: (a) receivingthe indicating data; (b) generating, using the received indicating data:(i) position data indicative of at least one of: (1) the position of thesensed coded data portion on the interface surface; and, (2) theposition of the sensing device relative to the interface surface; and,(ii) identity data indicative of the identity of the product item; and,(c) updating, using the identity data and the position data, the statusinformation. 6) The method of claim 1, wherein the interface surfaceincludes at least one region, including coded data indicative of anidentity of the at least one region, and wherein the method includes, inthe sensing device: (a) sensing the coded data disposed within the atleast one region; and, (b) generating, using the sensed coded data,indicating data indicative of the region identity. 7) The method ofclaim 6, wherein the method includes, in the computer system: (a)receiving the indicating data; (b) generating, using the receivedindicating data, region identity data indicative of the identity of theat least one region; (c) updating, using the identity of the at leastone region, the status information. 8) The method of claim 6, whereinthe at least one region represents a user interactive element. 9) Themethod of claim 1, wherein the method includes, in the sensing device:(a) selecting a status mode; and, (b) generating indicating dataindicative of the selected status mode. 10) The method of claim 9,wherein the method includes, selecting the status mode by at least oneof: (a) using an input provided on the sensing device; and, (b) sensingan interface surface, the interface surface including coded datadisposed thereon or therein, the sensing device being responsive to thecoded data to select the sensing mode. 11) The method of claim 9, themethod including, in the computer system: (a) receiving the indicatingdata; (b) generating, using the received indicating data: (i) identitydata indicative of the identity of the product item; and, (ii) mode dataindicative of the status mode; (c) updating, using the identity data andthe mode data, the status information. 12) The method of claim 1, themethod including, in the computer system: (a) selecting a status mode;(b) receiving the indicating data; (c) generating, using the receivedindicating data, identity data indicative of the identity of the productitem; (d) updating, using the identity data and the mode data, thestatus information. 13) The method of claim 12, wherein the methodincludes, selecting the status mode by at least one of: (a) using aninput provided on the computer system; and, (b) in the computer system:(i) receiving mode indicating data from a sensing device, the sensingdevice being responsive to sensing of coded data provided on arespective mode interface surface to generate indicating data indicativeof the status mode; (ii) generating, using the received indicating data,mode data indicative of the status mode; and, (iii) using the mode datato select the status mode. 14) The method of claim 1, wherein the methodincludes, in the computer system; (a) receiving the indicating data; (b)determining the product item identity; (c) determining a current productitem status from the product status information stored in the datastore; and, (d) updating the product status information in accordancewith the indicating data. 15) The method of claim 1, wherein theinterface surface includes at least one region having visible markingsrepresenting a respective product item status, the method including, inthe sensing device: (a) sensing coded data provided in the region; and,(b) generating, using the sensed coded data, indicating data indicativeof the respective product item status, the computer system beingresponsive to the indicating data to update the status information usingthe respective product item status. 16) The method of claim 1, whereinat least part of the product status information represents an inventory.17) The method of claim 16, wherein the method includes, in the computersystem: (a) determine, using the indicating data, identity dataindicative of the product item identity; and, (b) updating the inventoryusing the identity data. 18) The method of claim 17, wherein theinventory includes at least an indication of a predetermined number ofproduct items of respective product types, the method including, in thecomputer system: (a) determining, using the indicating data, the productitem type; (b) determining the number of product items of the respectiveproduct item type; (c) comparing the number of product items to thepredetermined number; and, (d) in response to the comparison, at leastone of: (i) providing an indication of the product item type on ashopping list; (ii) updating the product status information; and, (iii)taking no action. 19) The method of claim 1, wherein at least part ofthe product status information represents a shopping list. 20) Themethod of claim 19, wherein the method includes, in the computer system:(a) determine, using the indicating data, identity data indicative ofthe product item identity; and, (b) updating the shopping list using theidentity data. 21) A method of maintaining a status of a product item,the product item including an associated interface surface, theinterface surface having disposed thereon or therein coded dataincluding a number of coded data portions, each coded data portion beingindicative of an identity of the product item, the method including, ina computer system: (a) receiving indicating data from a sensing device,the sensing device being responsive to sensing of the coded data togenerate indicating data indicative of the identity of the product item;(b) generating, using the received indicating data, identity dataindicative of the identity of the product item; (c) update productstatus information stored in a data store. 22) The method of claim 21,wherein the coded data portions are provided at respective positions onthe interface surface, wherein each coded data portion is indicative ofthe respective position, wherein the sensing device generates, using atleast one sensed coded data portion, indicating data indicative of atleast one of a position of the sensed coded data portion on theinterface surface and a position of the sensing device relative to theinterface surface, and wherein the method includes, in the computersystem: (a) receiving the indicating data; (b) generating, using thereceived indicating data: (i) position data indicative of at least oneof: (1) the position of the sensed coded data portion on the interfacesurface; and, (2) the position of the sensing device relative to theinterface surface; and, (ii) identity data indicative of the identity ofthe product item; and, (c) updating, using the identity data and theposition data, the status information. 23) The method of claim 21,wherein the interface surface includes at least one region, includingcoded data indicative of an identity of the at least one region, whereinthe sensing device generates, using sensed coded data disposed withinthe at least one region, indicating data indicative of the regionidentity, and wherein the method includes, in the computer system: (a)receiving the indicating data; (b) generating, using the receivedindicating data, region identity data indicative of the identity of theat least one region; and, (c) updating, using the identity of the atleast one region, the status information. 24) The method of claim 21,wherein the interface surface includes at least one region havingvisible markings representing a respective product item status, whereinthe sensing device generates, using sensed coded data provided in theregion, indicating data indicative of the respective product itemstatus, and wherein the method includes, in the computer system: (a)receiving the indicating data; (b) generating, using the receivedindicating data, status data indicative of the product item status; and,(c) updating, using the status data, the status information. 25) Themethod of claim 21, wherein the sensing device, when operating in astatus mode and in response to sensing coded data, generates indicatingdata indicative of the status mode, and wherein the method includes, inthe computer system: (a) receiving the indicating data; (b) generating,using the received indicating data: (i) identity data indicative of theidentity of the product item; and, (ii) mode data indicative of thestatus mode; (c) determining, using the identity data and the mode data,an status request; and, (d) updating the status information using thestatus request. 26) The method of claim 21, the method including, in thecomputer system: (a) selecting a status mode; (b) receiving theindicating data; (c) generating, using the received indicating data,identity data indicative of the identity of the product item; (d)determining, using the identity data and the selected status mode, astatus request; and, (e) updating the status information using thestatus request. 27) The method of claim 26, wherein the method includesselecting the status mode by at least one of: (a) using an inputprovided on the computer system; and, (b) in the computer system: (i)receiving mode indicating data from a sensing device, the sensing devicebeing responsive to sensing of coded data provided on a respective modeinterface surface to generate mode indicating data indicative of thestatus mode; (ii) generating, using the received indicating data, modedata indicative of the status mode; and, (iii) using the mode data toselect the status mode. 28) The method of claim 21, wherein the methodincludes, in the computer system; (a) receiving the indicating data; (b)determining the product item identity; (c) determining a current productitem status from the product status information stored in the datastore; and, (d) updating the product status information in accordancewith the indicating data. 29) The method of claim 21, wherein at leastpart of the product status information represents an inventory. 30) Themethod of claim 29, wherein the method includes, in the computer system:(a) determine, using the indicating data, identity data indicative ofthe product item identity; and, (b) updating the inventory using theidentity data. 31) The method of claim 21, wherein the inventoryincludes at least an indication of a predetermined number of productitems of respective product types, the method including, in the computersystem: (a) determining, using the indicating data, the product itemtype; (b) determining the number of product items of the respectiveproduct item type; (c) comparing the number of product items to thepredetermined number; and, (d) in response to the comparison, at leastone of: (i) providing an indication of the product item type on ashopping list; (ii) updating the product status information; and, (iii)taking no action. 32) The method of claim 21, wherein at least part ofthe product 'status information represents a shopping list. 33) Themethod of claim 32, wherein the method includes, in the computer system:(a) determine, using the indicating data, identity data indicative ofthe product item identity; and, (b) updating the shopping list using theidentity data. 34) A method of maintaining a status of a product item,wherein the method includes providing the product item with anassociated interface surface, the interface surface having disposedthereon or therein coded data including a plurality of coded dataportions, each coded data portion being indicative of an identity of theproduct item such that when the coded data portion is sensed by asensing device, the sensing device generates indicating data indicativeof the product item identity, the indicating data being transferred to acomputer system which is responsive to the indicating data to updateproduct status information stored in a data store. 35) The method of anyone of claims 1, 21 and 34, wherein the status information includes anindication of the product item being at least one of: (a) purchased; (b)in use; and, (c) used. 36) The method of any one of claims 1, 21 and 34,wherein the coded data is substantially invisible to the unaided eye.37) The method of any one of claims 1, 21 and 34, wherein the coded datais printed using infrared ink. 38) The method of any one of claims 1, 21and 34, wherein each coded data portion is indicative of an EPCassociated with the product item. 39) The method of any one of claims 1,21 and 34, wherein the coded data is provided on the interface surfacecoincident with visible markings representing at least one of: (a)product information; (b) the identity of the product item; (c) productstatus information; and, (d) a status request. 40) The method of any oneof claims 1, 21 and 34, wherein the interface surface is at least aportion of at least one of: (a) product item packaging; (b) product itemlabelling; (c) product manuals; ( d) product instructions; and, (e) asurface of the product item. 41) The method of any one of claims 1, 21and 34, wherein the coded data is disposed over at least one of: (a)substantially all of any one of: (i) an entire product surface; (ii)packaging; and, (iii) a product label; (b) more than 25% of any one of:(i) an entire product surface; (ii) packaging; and, (iii) a productlabel; (c) more than 50% of any one of: (i) an entire product surface;(ii) packaging; and, (iii) a product label; (d) more than 75% of any oneof: (i) an entire product surface; (ii) packaging; and, (iii) a productlabel; 42) A sensing device for maintaining a status of a product item,the product item including an associated interface surface, theinterface surface having disposed thereon or therein coded dataincluding a plurality of coded data portions, each coded data portionbeing indicative of an identity of the product item, the sensing deviceincluding: (a) a sensor for sensing at least one coded data portion; (b)a processor for generating indicating data indicative of the productitem identity; and, (c) a communication means for transferring theindicating data to a computer system, the computer system beingresponsive to the indicating data to update product status informationstored in a data store. 43) The sensing device of claim 42, wherein thesensing device is adapted for use in the method of claim
 1. 44) Acomputer system for providing status information relating to a productitem, the product item including an associated interface surface, theinterface surface having disposed thereon or therein coded dataincluding a plurality of coded data portions, each coded data portionbeing indicative of an identity of the product item, wherein thecomputer system: (a) receives indicating data generated by a sensingdevice in response to sensing of at least one coded data portion, theindicating data being indicative of the product item identity; (b)generates, using the received indicating data, identity data indicativeof the identity of the product item; and, (c) updates, using theidentity data, the product status information stored in a data store.45) The computer system of claim 44, wherein the computer system isadapted for use in the method of claim
 21. 46) A product item, theproduct item having an associated interface surface, the interfacesurface having disposed thereon or therein coded data including aplurality of coded data portions, each coded data portion beingindicative of an identity of the product item such that when the codeddata portion is sensed by a sensing device, the sensing device generatesindicating data indicative of the product item identity, the indicatingdata being transferred to a computer system which is responsive to theindicating data to update product status information stored in a datastore.